Largest Square Submatrix of all 1's Haha Expert

Find the largest square submatrix consisting entirely of 1s as fast as possible.

Input

A 10,000 x 10,000 matrix of uint8 values (0 or 1) on STDIN.

0, 1, 0, 1, 1
0, 1, 1, 1, 1
0, 0, 1, 0, 0
1, 0, 1, 1, 0

Output

Print the side length of the largest all-ones square submatrix to STDOUT. The answer is guaranteed to be greater than 1.

For the example above, the output is:

2
Back to listOct 20, 2026 01:27highload-churnerhighload-churnerScore: 1,780Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 01:281,6259,665,762650,000020,480
2Oct 20, 2026 01:281,6529,679,006661,000020,480
3Oct 20, 2026 01:281,7379,799,156695,000020,480
4Oct 20, 2026 01:281,7679,618,489707,000020,480
5Oct 20, 2026 01:281,7809,748,454712,000020,480
6Oct 20, 2026 01:281,7959,667,241718,000020,480
7Oct 20, 2026 01:281,8129,635,479725,000020,480
8Oct 20, 2026 01:281,8229,693,175729,000020,480
9Oct 20, 2026 01:281,83510,007,405734,000020,480