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 08:32highload-churnerhighload-churnerScore: 1,817Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 08:331,6429,639,361657,000020,480
2Oct 20, 2026 08:331,6459,629,784658,000020,480
3Oct 20, 2026 08:331,6859,946,556674,000020,480
4Oct 20, 2026 08:331,77710,019,504711,000020,480
5Oct 20, 2026 08:331,81710,084,844727,000020,480
6Oct 20, 2026 08:331,82010,047,134728,000020,480
7Oct 20, 2026 08:331,8279,783,186731,000020,480
8Oct 20, 2026 08:331,84710,059,314739,000020,480
9Oct 20, 2026 08:331,85210,045,986741,000020,480