games – Dan Q

ChatGPT beats GeoGuessr

You’ve probably come across GeoGuessr already: it’s an online game where you (and friends, if you’ve got them) get dropped into Google Street View and have two minutes to try to work out where in the world you are and drop a pin on it.

A great strategy is to “walk around” a little, looking for landmarks, phone numbers, advertisements, linguistic clues, cultural indicators, and so on, narrowing down the region of the world you think you’re looking at before committing to a country or even a city. You’re eventually scored by how close you are to the actual location.

Cheating at GeoGuessr

I decided to see if ChatGPT can do better than me. Using only the free tier of both GeoGuessr and ChatGPT¹, I pasted screenshots of what I was seeing right into ChatGPT:

That’s pretty spooky, right?

The response came back plenty fast enough for me to copy-and-paste the suggested address into Google Maps, get the approximate location, and then drop a pin in the right place in GeoGuessr. It’s probably one of my most-accurate guesses ever.

This isn’t a one-off fluke. I tried again, this time using only a single photo, rather than one pointing in each direction on the street:

This time, it wasn’t quite right: the actual location of the photo was Chittagong, not Dhaka, about 200km away.

But that’s still reasonably spectacular from only a single vantage from a single point.

Obviously my approach here was crude, but it’d be relatively easy to, for example, implement a browser wrapper that cheated on-your-behalf: while playing GeoGuessr, you’d just click a “send to AI” button whenever you fancied and it’d start working in the background, improving precision with each subsequent screenshot (so you could still “walk around” and pass extra details to it).

And similarly, a little prompt manipulation could have the output include estimated GPS coordinates, allowing the code to place the pin for you while outputting its reasoning on the side².

The short of what I’m saying is: if you’re playing GeoGuessr against somebody you don’t trust not to cheat… they might well be cheating. And thanks to the explanatory output, they can even justify their explanations for the places they dropped pins.

What about other photos?

The other thought that comes to my mind is: could this be used to infer approximate geolocations from photos whose EXIF metadata has been stripped. Because if so, that’s the kind of thing that’s certain to get exploited by all kind of people who want to know where you are/were at a particular time. For example… law enforcement, stalkers, and other unsavoury types.

I wrote a prompt for gpt4o and put it to work:

1. Starting out easy

The Logos Hope docked at the Port of Spain cruise ship terminal, Trinidad & Tobago. — I took this photo from the balcony of our first hotel during Ruth and I’s trip to Trinidad & Tobago.

The AI guessed:

Location: Port of Spain, Trinidad and Tobago

Explanation: The photograph shows a large ship docked at a port with a building that displays the text “WELCOME TO PORT OF SPAIN”. This text is in English, indicating an English-speaking country. The mention of “Port of Spain” directly specifies the port’s location in the capital city of Trinidad and Tobago. The design and style of the port facilities, as well as the presence of a ship named “Logos Hope”, which is known to visit many ports globally, further suggests a Caribbean port, aligning with Port of Spain’s known characteristics.

Coordinates: 10.6549, -61.5011

✅ That was pretty easy, to be fair.

2. A little more challenging

A squat neolithic stone circle with many stones (some might say an uncountable number). A dog pulls at her lead to follow one of her humans more-closely around it. — We have an annual tradition of visiting this particular monument.

The AI guessed:

Location: The Rollright Stones, England, United Kingdom

Explanation: The photograph depicts an area with several ancient standing stones arranged in a circle in a rural setting, characteristic of a stone circle. These are typically found in certain parts of the UK. The terrain is typical of the British countryside, with a grassy field and surrounding trees. The specific arrangement and size of the stones, along with the style of fencing and walking paths, are reminiscent of the Rollright Stones, one of Britain’s historic sites known for a circle of Neolithic or Bronze Age standing stones located in Oxfordshire, England.

Coordinates: 51.9743, -1.5731

✅ Again, spot on. If you’d never been to the Rollright Stones, you probably wouldn’t get that one, because while it’s a distinctive-looking stone circle… it’s not that distinctive-looking, right? Let’s be honest: it’s some rocks in a field.

3. Ramping up the difficulty

The AI guessed:

Location: Istanbul, Turkey

Explanation: The photograph prominently features the Galata Tower in the background, a well-known landmark in Istanbul, Turkey. Moreover, the presence of a ferry or similar boat and the architectural style of the surrounding buildings are indicative of Istanbul’s famous skyline. The signage in Turkish, as suggested by the word partially visible on the left, also supports this location as Turkey is a predominantly Turkish-speaking country. These elements combined make it highly likely that the photograph was taken in Istanbul.

Coordinates: 41.0082, 28.9784

✅ The coordinates aren’t exactly right – it’s placed us in the city rather than on a boat, which we clearly are – but it’s not done badly. Spotting the Galata Tower³ was a nice move.

4. Okay, now hard mode:

Dan waves to the camera in front of a pleasure marina and revitalised docklands. — This photo is from 3Camp⁴ last year.

The AI guessed:

Location: Cardiff Bay, Cardiff, Wales, United Kingdom

Explanation: The photograph features a marina with modern residential buildings, which is characteristic of the Cardiff Bay area in Cardiff, Wales. The architecture, clear blue skies, and marina setting are reminiscent of Cardiff’s waterfront development. Additionally, the presence of English signage on the boat (“FINBAR”) supports a location in an English-speaking country. Cardiff Bay is known for its redeveloped waterfront area with modern apartments and leisure facilities surrounding the marina. The style and design of the building are consistent with developments in Cardiff’s revitalized docklands.

Coordinates: 51.4626, -3.1678

❌ Oops! Nope. I can see the thinking of what it’s claiming, there, but this was actually the Ipswich marina. I went for a walk to take a break from the code I’d been writing and took this somewhere in the vicinity of the blue plaque for Edward Ardizzone that I’d just spotted (I was recording a video for my kids, who’ve enjoyed several of his Tim… books).

So I don’t think this is necessarily a game-changer for Internet creeps yet. So long as you’re careful not to post photos in which you’re in front of any national monuments and strip your EXIF metadata as normal, you’re probably not going to give away where you are quite yet.

Footnotes

¹ And in a single-player game only: I didn’t actually want to cheat anybody out of a legitimate victory!

² I’m not going to implement GeoCheatr, as I’d probably name it. Unless somebody feels like paying me to do so: I’m open for freelance work right now, so if you want to try to guarantee the win at the GeoGuessr World Championships (which will involve the much-riskier act of cheating in person, so you’ll want a secret UI – I’m thinking a keyboard shortcut to send data to the AI, and an in-ear headphone so it can “talk” back to you?), look me up? (I’m mostly kidding, of course: just because something’s technically-possible doesn’t mean it’s something I want to do, even for your money!)

³ Having visited the Galata Tower I can confirm that it really is pretty distinctive.

⁴ 3Camp is Three Rings‘ annual volunteer get-together, hackathon, and meetup. People come together for an intensive week of making-things-better for charities the world over.

Giant strategy

White’s move. Mate in three. A giant chessboard is the perfect environment to teach a child some basic chess strategy, right?

More castles and mazes

Made a little progress on the game idea I’d been experimenting with. The idea is to do find a series of orthogonal (like a rook in chess!) moves that land on every square exactly once each before returning to the start, dodging walls and jumping pits.

But the squares have arrows (limiting the direction you can move out of them) or numbers (specifying the distance you must travel from them).

Every board is solvable, starting from any square. There’ll be a playable version to use on your device (with helpful features like “undo”) sometime soon, but for now you can give them a go by hand, if you like this kind of puzzle!

Voice of America

In light of Trump’s attempts to axe Voice of America, because it is, he claims, “anti-Trump” (and because he’s so insecure that he can’t stand the thought that taxpayer dollars might go to anybody who disagrees with him in any way, for any reason), I’ve produced a suggested update to the rules of Twilight Struggle for the inevitable 9th printing:

Yet another blow to US soft power in order to appease the ego of convicted felon Donald Trump. Sigh.

Castles and mazes

Possibly I’m a little late for the “casual daily puzzle game” party. (Did Wordle already get invented in this timeline; I forget?)

I think there’s something in an idea I’ve been toying with. Bring on the weekend, when I can throw some brainpower at the frontend code!

It’s not cheating if you write the video game solver yourself

This is a repost promoting content originally published elsewhere. See more things Dan's reposted.

…

I didn’t know how to solve the puzzle, but I did know how to write a computer program to solve it for me. That would probably be even more fun, and I could argue that it didn’t actually count as cheating. I didn’t want the solution to reveal itself to me before I’d had a chance to systematically hunt it down, so I dived across the room to turn off the console.

I wanted to have a shower but I was worried that if I did then inspiration might strike and I might figure out the answer myself. So I ran upstairs to my office, hit my Pomodoro timer, scrolled Twitter to warm up my brain, took a break, made a JIRA board, Slacked my wife a status update, no reply, she must be out of signal. Finally I fired up my preferred assistive professional tool. Time to have a real vacation.

…

Robert Heaton

Obviously, I’d be a fan of playing your single-player video game any damn way you like. But beyond that, I see Robert’s point: there are some puzzles that are just as much (or more) fun to write a program to solve than to solve as a human. Digital jigsaws would be an obvious and ongoing example, for me, but I’ve also enjoyed “solving” Hangman (not strictly a single-player game, but my “solution” isn’t really applicable to human opponents anyway), Mastermind (this is single-player, in my personal opinion – fight me! – the codemaster doesn’t technically have anything “real” to do; their only purpose is to hold secret information), and I never got into Sudoku principally because I found implementing a solver much more fun that being a solver.

Anyway: Robert’s post shows that he’s got too much time on his hands when his wife and kids are away, and it’s pretty fun.

It is as if you were on your phone

This is a repost promoting content originally published elsewhere. See more things Dan's reposted.

Being on your phone all the time and while also not being on your phone all the time has never been more important.

“It is as if you were on your phone” is a phone-based experience for pretending to be on your phone without needing to be on your phone. All from the comfort of your phone.

Relax and blend in with familiar gestures and realistic human behaviour.

Pippin Barr

When I tried this fun and experimental game, I was struck by a feeling of deja vu. Was this really new? It felt ever so familiar.

Turns out, it draws a lot of inspiration from its 2016 prequel, It is as if you were playing chess. Which I’d completely forgotten about until just now.

It really is almost as if I were on my phone.

Anyway, It is as if you were on your phone is… well, it’s certainly a faithful simulation of what it would be like to be on my phone. If you saw me, you’d genuinely think that I was on my phone, even though in reality I was just playing It is as if you were on your phone on my phone. That’s how accurate it is.

Give it a go on your phone and see if you agree.

Rewilding Slay

I’ve been playing Sean O’Connor’s Slay for around 30 years (!), but somehow it took until today, on the Android version, before I tried my hand at “rewilding” the game world.

The rules of the game make trees… a bad thing: you earn no income from hexes with them. But by the time I was winning this map anyway, I figured that encouraging growback would be a pleasant way to finish the round.

Play your videogames any damn way you want. Don’t let anybody tell you there’s a right or wrong way to enjoy a single-player game. Today I took a strategy wargame and grew a forest. How will you play?

Lego: Zero Dawn

Except to children, I don’t really give Christmas presents to (or expect to receive them from) others any more.

But that didn’t stop my buying myself a gift of a particularly fun Lego set to build over the festive period (with a little help from the eldest child!).

Note #25375

Today, while I cooked dinner, I introduced my two children (aged 10 and 8) to Goat Simulator.

Within half an hour, they’d added an imaginative twist and a role-playing element. My eldest had decreed themselves Angel of Goats and the younger Goat Devil and the two were locked in an endless battle to control the holy land at the top of a rollercoaster.

The shrieks of joy and surprise from the living room could be heard throughout the entire house. Perhaps our whole village.

Harswell Steel

My past self, receiving a copy of Transport Tycoon for his 14th birthday, would have his mind blown if he could see the kind of insanely-complex super-stations that are possible in (the open-source successor to) the game 30 years on.

Of course, this kind of thing – multiple simultaneously shared in-and-out routes on a bidirectional station – wasn’t (sensibly) possible before the introduction of path-based signalling in OpenTTD 0.7.0. And modern path-based signals in the game are even smarter.

But still, 14-year-old me had a dream. And nowadays that dream is real.

Note #24972

Future Arimaa grand masters at practice, this Sunday morning boardgaming session.

Double Sausages

This child is eating sausages with one hand while playing a video game about eating sausages with the other.

Is this life-imitating-art or the other way around? Who can possibly say?

Note #24701

Playing simultaneous games against both children might have been less challenging if they hadn’t both kept trying to start fights with one another at the same time! 😂

D20 with Advantage

Dungeons & Dragons players spend a lot of time rolling 20-sided polyhedral dice, known as D20s.

In general, they’re looking to roll as high as possible to successfully stab a wyvern, jump a chasm, pick a lock, charm a Duke¹, or whatever.

A 'full set' of white polyhedral dice commonly-used by roleplayers - a D4, D6, D8, two D10s, a D12, and a D20 - sit half-submerged in a red liquid. — Submerging your dice set in the blood of a halfling is a sure-fire way to get luckier rolls.

Roll with advantage

Sometimes, a player gets to roll with advantage. In this case, the player rolls two dice, and takes the higher roll. This really boosts their chances of not-getting a low roll. Do you know by how much?

I dreamed about this very question last night. And then, still in my dream, I came up with the answer². I woke up thinking about it³ and checked my working.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
2	2	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
3	3	3	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
4	4	4	4	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
5	5	5	5	5	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
6	6	6	6	6	6	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
7	7	7	7	7	7	7	7	8	9	10	11	12	13	14	15	16	17	18	19	20
8	8	8	8	8	8	8	8	8	9	10	11	12	13	14	15	16	17	18	19	20
9	9	9	9	9	9	9	9	9	9	10	11	12	13	14	15	16	17	18	19	20
10	10	10	10	10	10	10	10	10	10	10	11	12	13	14	15	16	17	18	19	20
11	11	11	11	11	11	11	11	11	11	11	11	12	13	14	15	16	17	18	19	20
12	12	12	12	12	12	12	12	12	12	12	12	12	13	14	15	16	17	18	19	20
13	13	13	13	13	13	13	13	13	13	13	13	13	13	14	15	16	17	18	19	20
14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	15	16	17	18	19	20
15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	16	17	18	19	20
16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	17	18	19	20
17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	18	19	20
18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	19	20
19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	20
20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20

Table illustrating the different permutations of two D20 rolls and the “advantage” result (i.e. the higher of the two).

The chance of getting a “natural 1” result on a D20 is 1 in 20… but when you roll with advantage, that goes down to 1 in 400: a huge improvement! The chance of rolling a 10 or 11 (2 in 20 chance of one or the other) remains the same. And the chance of a “crit” – 20 – goes up from 1 in 20 when rolling a single D20 to 39 in 400 – almost 10% – when rolling with advantage.

You can see that in the table above: the headers along the top and left are the natural rolls, the intersections are the resulting values – the higher of the two.

The nice thing about the table above (which again: was how I visualised the question in my dream!) is it really helps to visualise why these numbers are what they are. The general formula for calculating the chance of a given number when rolling D20 with advantage is ( n² – (n-1)² ) / 400. That is, the square of the number you’re looking for, minus the square of the number one less than that, over 400 (the total number of permutations)⁴.

Why roll two dice when one massive one will do?

Knowing the probability matrix, it’s theoretically possible to construct a “D20 with Advantage” die⁵. Such a tool would have 400 sides (one 1, three 2s, five 3s… and thirty-nine 20s). Rolling-with-advantage would be a single roll.

This is probably a totally academic exercise. The only conceivable reason I can think of would be if you were implementing a computer system on which generating random numbers was computationally-expensive, but memory was cheap: under this circumstance, you could pre-generate a 400-item array of possible results and randomly select from it.

But if anybody’s got a 3D printer capable of making a large tetrahectogon (yes, that’s what you call a 400-sided polygon – you learned something today!), I’d love to see an “Advantage D20” in the flesh. Or if you’d just like to implement a 3D model for Dice Box that’d be fine too!

Footnotes

¹ Or throw a fireball, recall an anecdote, navigate a rainforest, survive a poisoning, sneak past a troll, swim through a magical swamp, hold on to a speeding aurochs, disarm a tripwire, fire a crossbow, mix a potion, appeal to one among a pantheon of gods, beat the inn’s landlord at an arm-wrestling match, seduce a duergar guard, persuade a talking squirrel to spy on some bandits, hold open a heavy door, determine the nature of a curse, follow a trail of blood, find a long-lost tome, win a drinking competition, pickpocket a sleeping ogre, bury a magic sword so deep that nobody will ever find it, pilot a spacefaring rowboat, interpret a forgotten language, notice an imminent ambush, telepathically commune with a distant friend, accurately copy-out an ancient manuscript, perform a religious ritual, find the secret button under the wizard’s desk, survive the blistering cold, entertain a gang of street urchins, push through a force field, resist mind control, and then compose a ballad celebrating your adventure.

² I don’t know what it says about me as a human being that sometimes I dream in mathematics, but it perhaps shouldn’t be surprising given I’m nerdy enough to have previously recorded instances of dreaming in (a) Perl, and (b) Nethack (terminal mode).

³ When I woke up I also found that I had One Jump from Disney’s Aladdin stuck in my head, but I’m not sure that’s relevant to the discussion of probability; however, it might still be a reasonable indicator of my mental state in general.

⁴ An alternative formula which is easier to read but harder to explain would be ( 2(n – 1) + 1 ) / 400.

⁵ Or a “D20 with Disadvantage”: the table’s basically the inverse of the advantage one – i.e. 1 in 400 chance of a 20 through to 39 in 400 chance of a 1.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
2	2	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
3	3	3	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
4	4	4	4	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
5	5	5	5	5	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
6	6	6	6	6	6	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
7	7	7	7	7	7	7	7	8	9	10	11	12	13	14	15	16	17	18	19	20
8	8	8	8	8	8	8	8	8	9	10	11	12	13	14	15	16	17	18	19	20
9	9	9	9	9	9	9	9	9	9	10	11	12	13	14	15	16	17	18	19	20
10	10	10	10	10	10	10	10	10	10	10	11	12	13	14	15	16	17	18	19	20
11	11	11	11	11	11	11	11	11	11	11	11	12	13	14	15	16	17	18	19	20
12	12	12	12	12	12	12	12	12	12	12	12	12	13	14	15	16	17	18	19	20
13	13	13	13	13	13	13	13	13	13	13	13	13	13	14	15	16	17	18	19	20
14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	15	16	17	18	19	20
15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	16	17	18	19	20
16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	17	18	19	20
17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	18	19	20
18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	19	20
19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	20
20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
2	2	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
3	3	3	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
4	4	4	4	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
5	5	5	5	5	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
6	6	6	6	6	6	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
7	7	7	7	7	7	7	7	8	9	10	11	12	13	14	15	16	17	18	19	20
8	8	8	8	8	8	8	8	8	9	10	11	12	13	14	15	16	17	18	19	20
9	9	9	9	9	9	9	9	9	9	10	11	12	13	14	15	16	17	18	19	20
10	10	10	10	10	10	10	10	10	10	10	11	12	13	14	15	16	17	18	19	20
11	11	11	11	11	11	11	11	11	11	11	11	12	13	14	15	16	17	18	19	20
12	12	12	12	12	12	12	12	12	12	12	12	12	13	14	15	16	17	18	19	20
13	13	13	13	13	13	13	13	13	13	13	13	13	13	14	15	16	17	18	19	20
14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	15	16	17	18	19	20
15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	16	17	18	19	20
16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	17	18	19	20
17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	18	19	20
18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	19	20
19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	20
20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
1	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
2	2	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
3	3	3	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
4	4	4	4	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
5	5	5	5	5	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
6	6	6	6	6	6	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
7	7	7	7	7	7	7	7	8	9	10	11	12	13	14	15	16	17	18	19	20
8	8	8	8	8	8	8	8	8	9	10	11	12	13	14	15	16	17	18	19	20
9	9	9	9	9	9	9	9	9	9	10	11	12	13	14	15	16	17	18	19	20
10	10	10	10	10	10	10	10	10	10	10	11	12	13	14	15	16	17	18	19	20
11	11	11	11	11	11	11	11	11	11	11	11	12	13	14	15	16	17	18	19	20
12	12	12	12	12	12	12	12	12	12	12	12	12	13	14	15	16	17	18	19	20
13	13	13	13	13	13	13	13	13	13	13	13	13	13	14	15	16	17	18	19	20
14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	15	16	17	18	19	20
15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	16	17	18	19	20
16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	16	17	18	19	20
17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	17	18	19	20
18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	19	20
19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	20
20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20