Buggy python submission (verdict: Time Limit Exceeded):
def counting(k, v, square):
    square += 1
    for _ in range(square):
        for r in range(k, k + square):
            if r > len(matrix) - 1:
                return False
            for c in range(v, v + square):
                if c > len(matrix[k]) - 1:
                    return False
                if matrix[r][c] == '1':
                    return False
        return True


line = input().split(' ')

answer = [[0 for _ in range(int(line[1]))] for _ in range(int(line[0]))]
matrix = []
maximum = 0

for _ in range(int(line[0])):
    row = input().split(' ')
    matrix.append(row)

    for i in range(len(matrix)):
            for j in range(len(matrix[i])):
                for m in range(min(int(line[0]), int(line[1]))):
                    res = counting(i, j, maximum)
                    # print(res)
                    if res:
                        maximum += 1
                    else:
                        break

print(maximum * maximum)

Fixed submission:
def solve2():
    r, c = map(int, input().split(' '))

    ans_matrix = [[0 for _ in range(c + 1)] for _ in range(r + 1)]
    input_matrix = []

    for _ in range(r):
        input_matrix.append(list(map(int, input().split(' '))))

    largest_square = 0

    for i in range(len(input_matrix)):
        for j in range(len(input_matrix[i])):
            new_i, new_j = i + 1, j + 1
            if input_matrix[i][j] == 0:
                ans_matrix[new_i][new_j] = min(ans_matrix[new_i - 1][new_j], ans_matrix[new_i][new_j - 1], ans_matrix[new_i - 1][new_j - 1]) + 1
                largest_square = ans_matrix[new_i][new_j] if ans_matrix[new_i][new_j] > largest_square else largest_square
            else:
                ans_matrix[new_i][new_j] = 0

    print(largest_square ** 2)


def main():
    solve2()


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
def counting(k, v, square):
    square += 1
    for _ in range(square):

        for r in range(k, k + square):
            if r > len(matrix) - 1:
                return False
            for c in range(v, v + square):
                if c > len(matrix[k]) - 1:
                    return False
                if matrix[r][c] == '1':
                    return False
        return True


line = input().split(' ')

answer = [[0 for _ in range(int(line[1]))] for _ in range(int(line[0]))]
matrix = []
maximum = 0
is_over = False
ggg = 0
for _ in range(int(line[0])):
    row = input().split(' ')
    matrix.append(row)

for i in range(len(matrix)):
    for j in range(len(matrix[i])):
        ggg += 1
        for m in range(min(int(line[0]), int(line[1]))):
            res = counting(i, j, maximum)
            if res:
                maximum += 1
            else:
                break

print(maximum * maximum)

Fixed submission:
def solve2():
    r, c = map(int, input().split(' '))

    ans_matrix = [[0 for _ in range(c + 1)] for _ in range(r + 1)]
    input_matrix = []

    for _ in range(r):
        input_matrix.append(list(map(int, input().split(' '))))

    largest_square = 0

    for i in range(len(input_matrix)):
        for j in range(len(input_matrix[i])):
            new_i, new_j = i + 1, j + 1
            if input_matrix[i][j] == 0:
                ans_matrix[new_i][new_j] = min(ans_matrix[new_i - 1][new_j], ans_matrix[new_i][new_j - 1], ans_matrix[new_i - 1][new_j - 1]) + 1
                largest_square = ans_matrix[new_i][new_j] if ans_matrix[new_i][new_j] > largest_square else largest_square
            else:
                ans_matrix[new_i][new_j] = 0

    print(largest_square ** 2)


def main():
    solve2()


if __name__ == '__main__':
    main()