Given a matrix you need to find the submatrix with the largest number of elements, where the GCD (Greatest Common Divisor) of its elements is greater than one. A submatrix of the matrix is a sub-section composed of contiguous rows and columns of the original matrix.
Input
Two numbers n,m in the first line. Followed by n lines with m numbers in each line.
Constraints
1<=N,M<=200
1<=numbers<=10000
Output
Just a largest area where GCD is greater than 1.
Sample Input
3 3
2 6 8
4 8 3
6 9 4
Sample Output
4
If you observe the following submatrix:
2 6
4 8
The GCD is 2. There is no matrix larger than this with a GCD > 1.