# coding: utf8

__author__ = 'seven.wang'


class Solution(object):
    def maximalSquare(self, matrix):
        """
        :type matrix: List[List[str]]
        :rtype: int
        """




list1 = (
    [[1, 0, 1, 0, 0],
    [1, 0, 1, 1, 1],
    [1, 1, 1, 1, 1],
    [1, 0, 0, 1, 0]])
print Solution().maximalSquare(list1)