@staticmethod
def a():
    x = [int(x) for x in sys.stdin.readline().split()]
    for i in range(5):
        if (x[i] != (i + 1)):
            print((i + 1))
            break
@staticmethod
def a():
    x = [int(x) for x in sys.stdin.readline().split()]
    for i in range(5):
        if (x[i] != (i + 1)):
            print((i + 1))
            break