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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:

7351656111

7312812711

7258444124

9678779887

9411703169

7412861291

7351363076

7411634596

7478770530

8530884783

5842605790

2563474784

1185475794

7457774704

4140504451

3733361733

8959885989

8877781797

4643434173

5647918658

7947065445

4648583514

4603535340

5941454954

3627923297

7648647626

0725002570

2213212263

9684495480

5055440555

6666995665

7240095760

2231141265

7117292263

6923341785

8585490469

1575639543

4783230530

0648771440

5049071540

6305776330

3322230922

4345447543

0618861480

5927979952

7117110177

4535573534

3999938918

9998938993

1871610534

3446138977

7285270914

9644230533

8138177593

9558140574

9501718624

3841410707

3354781524

9846119464

4551411414

3304743340

3751431755

1077004717

2031961033

9521688915

6221175656

9290963813

1381338118

9291199729

6609666666

3029430934

9530909390

9447494979

0065560915

8033962903

7379917239

0225817919

2407667279

8789660205

0192662005

2504567979

3210690960

1182165846

4768735544

1236890230

4763375346

3330330830

6404420264

8595596573

1195165951

2395002618

1020662698

2986657672

6388657721

5855558752

2552292525

5375553678

7640465041

1079907912

0516939316

5511950771

3918638779

5086987936

0641994024

2059995292

3586883558

5511212551

1988498891

0900086074

7667677661

5338258234

7778779087

7200259071

1979079086

1250676036

1352375071

9597178674

9022922929

6295263259

7711212712

1931737337

1921909087

1842222695

9011235172

1045209200

7006789562

## The puzzle

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

5108585058

0260606662

0081308810

4827178672

0080586294

0740762020

5741519048

4787378786

5005633505

0259652091

1368998186

6221611122

8400110010

6250161513

6120605437

1401652742

0408142782

2189603142

9618176558

6235395095

9690673149

3316472028

7662778226

5529576599

1559595185

4296692642

0085565058

4222222248

9699297292

4343302234

5645556624

3347452214

0787352248

1925097214

2630852218

2517953224

2888036058

3826449008

7674818716

9669235468

3885935798

3331149361

0800838006

5556665458

3109113310

6491378734

3491177225

5298878221

3325672321

0440773904

5255282125

2001772021

3203087230

2128568325

8922350112

1964328851

8919739355

1349544165

8919918619

1324731427

3088888888

1361561115

7942332242

7394222292

1309553038

3132033231

7203932733

7894989085

4135564546

4204298104

7389967920

2303534660

7740347135

4400049401

6233268323

1119914902

6677694427

4796119301

0393149195

8901499325

9686749303

7177474630

4627114446

2101614432

4901292680

2624998629

3808373880

4414504415

2313182631

4134313146

5864625846

0088866478

0953955878

3697855476

5418151458

5252525592

9408065840

0565555046

4884458874

1916528973

4779236889

1676247689

1074907731

1047317117

4999999489

8674574788

5214545551

1076261617

8425919786

8850513081

1014882500

7350748021

7460556561

8325882888

3736963669

1850718101

8018010000

3678267628

7236767277

1340311364

9015510109

2330764461

7015256747

3230553323

8638533548

7011515828

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