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 00:53highload-churnerhighload-churnerScore: 1,862Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 00:541,7629,672,161705,000024,576stderr
2Oct 20, 2026 00:541,83510,126,958734,000024,576stderr
3Oct 20, 2026 00:541,86010,126,011744,000024,576stderr
4Oct 20, 2026 00:541,8629,744,589745,000024,576stderr
5Oct 20, 2026 00:541,86210,065,893745,000024,576stderr
6Oct 20, 2026 00:541,86210,106,370745,000024,576stderr
7Oct 20, 2026 00:541,8829,719,205753,000024,576stderr
8Oct 20, 2026 00:541,89510,116,039758,000024,576stderr
9Oct 20, 2026 00:542,24510,270,126898,000024,576stderr