mtx = None
mtx_len = None


def read_input():
    with open('input.txt', 'r') as fin:
        mtx = [[int(num) for num in line.split(' ')] for line in fin]

    mtx_len = len(mtx)


def associativity():
    for i in range(mtx_len):
        for j in range(mtx_len):
            for k in range(mtx_len):
                if mtx[mtx[i][j]][k] != mtx[i][mtx[j][k]]:
                    return False
    return True


def neutral_element():
    for i in range(mtx_len):
        if mtx[i] == [i for i in range(mtx_len)]:
            return i
    return None


def inverse_element():
    e = neutral_element()
    if e == None:
        return False
    cnt = 0
    for i in range(mtx_len):
        for j in range(mtx_len):
            if (mtx[i][j] == e) and (mtx[j][i] == e):
                cnt += 1
                break
    if cnt == mtx_len:
        return True
    else:
        return False


def commutativity():
    for i in range(mtx_len):
        for j in range(mtx_len):
            if mtx[i][j] != mtx[j][i]:
                return False
    return True


def closure():
    for i in range(mtx_len):
        for j in range(mtx_len):
            if mtx[i][j] not in range(mtx_len):
                return False
    return True


if __name__ == '__main__':
    read_input()