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# 2012-11-17: Puzzle - First to solve wins

For years I've had an idea in my head about a way to hide some information in a bunch of numbers. I actually got around to coding an implementation and figured I'd run a competition. The first person who figures out what the famous landmark is described by the second set of numbers below and posts the correct answer in the comments wins $100.

## The hint

Here's a hint. The following numbers are a reference to the Eiffel tower:

1235451724

1678405152

6372142800

2678145804

8373177337

8235733553

7668486786

1832222223

2304404309

0412055750

6428162656

9903646960

5266852710

0886556680

2514202714

7377763770

9265552956

4646648664

9805779578

7257927925

9883588833

2339779233

9533725330

7853981514

2581882739

0487708304

2255724272

0043736543

6013204861

6069215925

3070342940

6483778483

3049994903

1273317322

0913229936

0240822408

6081742290

5603795879

8419848679

5368098670

9911191410

9596945390

4997744279

9998896879

9989668699

3578759732

4473089032

9748859771

9150051856

5155531551

4988189641

0671380736

1102551602

0900709877

6004434406

3032434262

7533303757

4226334602

0910431652

7526941062

4021109066

1791744602

2704833766

4148599111

0150777701

6690678124

6387071101

3522753827

7171887171

3633696783

7971079104

1905401914

6270770128

8886858786

0979991079

9099997902

1777450708

8973438709

0010530778

9095894189

0226411979

7594757794

7539639569

6128460186

7883777837

7924703888

7988712247

7183688292

7113382120

7988714216

3524222542

6768575876

1935253394

8829191188

3538942059

1965997514

1951143175

3599198551

3765137321

8736158993

1734657168

1794657652

3729186821

8569595558

8724427824

9895159989

1437611137

3186685861

4237152538

5907524469

1713613562

8196414508

8832316438

1551158461

0810212008

3454324534

9939903899

8465724758

8865661268

0868306699

8239723838

8135338133

5869159155

8888668868

2464747267

7226337229

## The puzzle

Given the above hint, what famous landmark do the numbers below refer to?

9931811391

1721016101

7644474766

6528156825

7231966872

1925910173

1228027635

1528816810

7644836051

1332538959

7733322570

6335592224

7035524453

6052558660

6335565663

7739599357

1407001070

7073673660

3051330506

9494222941

7737353773

4899598954

5845632976

2319744954

4128058644

4056153504

9161353546

7797077790

0444440784

9858618756

8297997882

2909053896

5628013714

5915877852

0095117690

5150178782

7007220927

5575465524

7333553475

5958118598

7766058528

4660318424

4589975923

5675913413

2262100995

7392399377

1455455051

9951599555

4080558050

4498366871

1351519385

9350539716

9351495748

7447461414

9722972919

4433433442

4662265624

4516555161

7215235419

2603256969

5347183661

8936953061

9576872968

0724351672

8074078521

0234078825

6078218866

9951951592

5036366830

7161617677

1157178561

3233323326

1635766238

3866624768

3559576962

5892076752

0118770168

0277267462

2442294232

9196966951

3006006730

3733930973

6664691460

2222262022

2369737639

8675430939

0899697060

3671092423

8797510979

1975191977

7028195695

8977274692

5673974850

1422695393

3437575337

6523536652

4944974092

0788576850

3413194183

5828878627

5258284688

4760226653

5970418258

0288710287

8788888874

3634644633

1857126158

7882708727

5088787880

2485328345

9221020082

4849339449

2241788515

2881367480

2081306653

5225300031

2821639804

2330144930

2810907429

2816842150

5316108417

9340139303

2412712447

9016616610

4334113331

5850885150

Post the answer as a comment below. ~~The first person to answer correctly with an acceptable explanation to how the answer was reached (rather than just a guess) wins $100, so make sure to use your correct e-mail address so I can contact you.~~

**Note #1:** People have noted that the numbers change whenever the page is reloaded. That's as expected. This puzzle is *not* an *encryption* as much as it is an *obfuscation*. That the numbers change is not important, as only the pattern in them will lead to the answer, which is of course constant.

**Note #2:** There was a bug in my post for a short while, which made the hint and puzzle basically the resolve to the same answer. This is fixed now. If you saved a copy the numbers before, just grab a fresh set.

## Solved!

The second landmark was discovered by Batuhan Bozkurt, congratulations! The challenge has not yet been met entirely, though so I've decided to set a new challenge with the same method. ~~The same $100 prize applies~~.

Redditor Bearasaurus has solved the final challenge too! For hints, check the followup post.

## Comments

Big Ben

I'm afraid Big Ben is not it. But be sure to include some explanation as to how the answer was reached, so I know it isn't just a random guess.

I "solved" your puzzle, but I assume not in the way you wanted.

After giving it quite some hours, I failed to find any specific pattern (with a reasonable kolmogorov complexity) that would lead me to an answer. But in Reddit, you mentioned that you would be interested in statistical approaches that would lead to an answer (which I assume you are interested for increasing the security of the obfuscation?) so I exploited the fact that your website gives fresh batch of numbers at each reload so I grabbed about 1000 sets (with intervals in between, hopefully not causing trouble to your website, it handled the requests like a champ) and got to cracking.

Now your HTML formatting implies 10x10 blocks of data for each set. So that was a starting point when I first began looking at the problem. The grid is 70 x 20 so that implies 14 secret codes, 7 for each row.

I looked for what was common for each 10x10 block in each of the samples I gathered from your site. I found out that for each 10x10 block some digits occasionally never appears; for example in block 0x 0y, not all digits have to appear but one always appears at least once.

Once I looked at the remaining digits (that are common in all blocks at a particular coordinate), for the "hint", I was faced by these digits:

0485130

0021739

These are the coordinates in the form of degrees-minutes-seconds (dddmmss as you gave away generously in Reddit) of Eiffel Tower.

Once I ran the same process for the puzzle, the result was:

0295845

0310804

Which is the coordinates for the Great Pyramid of Giza.

Maybe this is disappointing, I don't know. If the website hadn't provided fresh batch of numbers, this method would not work. I assume, to strengthen the obfuscation, you could make sure one digit always appears at least once; but as long as the distribution isn't random, I suppose the answer could be extracted.

I've tried many approaches before this; I'm pretty confident that the pattern is not based on neighborhood relationships (as the answer can appear on edges, though wrapping around could be employed but still with it I failed to detect any patterns). I think it doesn't have anything (or much) to do with arithmetic on the digits (like summing / subtracting them). I tried various row/column patterns and couldn't come up with anything.

I also analyzed the 10x10 blocks containing the answer digits only once (so if the answer is 0 for that block, 0 appears only once in that block). But saw no obvious pattern at all. So this beats me in that regard.

If I am eligible for the prize for my answer, I would kindly ask you to donate it to the Doctors Without Borders foundation. If you are uncomfortable about it for some reason, you can choose to donate it somewhere else you see fit.

Thanks for the challenge, and although my curiosity has been partly satisfied, I'm still waiting for the answer that will allow me to solve this using a pen and paper using a single set of numbers.

Batuhan, the answer is indeed correct. The Great Pyramid of Giza is the one I was looking for. The method you used is indeed not the one I was hoping for, as you haven't actually figured out the way the coordinates are encoded into the sets of numbers.

Still, I'm not one to dictate how the problem should be solved. I will make a donation to Doctors Without Borders for $100 in your name and post proof that I have done so.

Since I would very much like for somebody to solve the method, I'm including this static problem for a second attempt, and another $100. Being in a comment, the following set obviously does not change and encodes a third landmark.

2626513077384364666346599932245309032974209496921885110948315551555613

6549028370497764766953274173448611231555969009312435020244378244262894

9308377132331493394457637801172312372974892873367485438142538547446457

5987478672136633636156339295109196283474021313920015080695500005010510

9318473400638833698356337893287640679475088481921818727043921551931599

5758758671181690400516397336912974972974211231362065019596695870416497

1701226107698865022553554534544375771374969996927993180831110067651597

3203310324331357320447629709425333533533932743923435767555759732852649

0008077080336367751344339394399228589625005440340517458583553308156594

7467243472134765226056779555595344734475199118911888022882025906466417

0332300493776667648725560571112261196221231229957486429403779342535143

1366338577707417047142278890548676887286598087756091175002210326130060

5863902088494574497542911473583959753975898054668946115111760583633056

3673921092972792959782223331128568968982838265801286279605628360969080

5301986352763553665223261861393193111359891776463941295493449120391390

0463999640662807648743557375531417213379281451584481179187119326988940

4352555243298062697573961379660934698929891289118894828988929160129317

1871110111741174649945428445570098658283038728302510575750510526949009

3326333663020967498782260828822839081251556075505536114445618120357157

5602990599311067698721073220721651596922796029092045295295550390501233

The challenge now is to find the answer and a step by step description of how to extract the correct digits from it.

## Post a comment