题解 | #判断两个IP是否属于同一子网#

# 优秀解法
import sys


def check(s):
    l = s.split('.')
    if len(l) != 4:
        return False
    for i in l:
        i = int(i)
        if  0> i or i > 255:
            
            return False
    return True

def check_mask(s):
    l = s.split('.')
    r = ''
    for i in l:
        a = bin(int(i))[2:].rjust(8,'0')
        r+=a
    
    if r.find('0') < r.rfind('1'):
        return False
    else:
        return True 

def same(ip1,ip2,mask):
    l1 = ip1.split('.')
    l2 = ip2.split('.')
    l3 = mask.split('.')
    s1 = []
    s2 = []
    for i,j in zip(l1, l3):
        s1.append(int(i)&int(j))
    for i,j in zip(l2, l3):
        s2.append(int(i)&int(j))
    if s1 == s2:
        return True
    else:
        return False
        

while True:
    try:
        mask = input().strip()
        ip1 = input().strip()
        ip2 = input().strip()

        if check(ip1) and check(ip2) and check(mask) and check_mask(mask):
            if same(ip1, ip2, mask):
                print('0')
            else:
                print('2')
        else:
            print('1')
    except:
        break