# Given a matrix of dimensions mxn having all entries as 1 or 0,
# find out the size of maximum size square sub-matrix with all 1s.

A = [[1, 0, 1, 1, 1, 0, 0],
     [0, 0, 1, 1, 1, 1, 1],
     [0, 0, 1, 1, 1, 1, 1],
     [1, 1, 1, 1, 1, 0, 1],
     [0, 0, 1, 0, 1, 0, 0]]


