from math import gcd
def solve(n, m, input_list):
    mat = [[[0] *m] *n] *n
    res = 0
    for i in range(n):
        for j in range(i, n):
            gcd_temp = 0
            x = 0
            for k in range(m):
                if i == j:
                    mat[i][j][k] = input_list[i][k]
                else:
                    mat[i][j][k] = gcd(mat[i][j-1][k], input_list[j][k])
                gcd_temp = gcd(gcd_temp, mat[i][j][k])
                if gcd_temp > 1:
                    x += j - i + 1
                else:
                    res = max(res,x)
                    if mat[i][j][k] > 1:
                        gcd_temp = mat[i][j][k]
                        x = j - i + 1
            res = max(res,x)
    return res
print(solve(3, 4, [[3, 7, 9, 12], [5, 9, 4, 6], [7, 8, 5, 10]]))

3, 4, [[3, 7, 9, 12], [5, 9, 4, 6], [7, 8, 5, 10]]

3