题解 | #判断两个IP是否属于同一子网#

import sys
import re

#笑死了，我被前面一道检测子网是否有效的题搞到ptsd了，中间一段comment掉的是检测每段是否全1or0的
zi = input().split(".")
ip1 = input().split(".")
ip2 = input().split(".")

def ifzi(zi):
    to_bin = ""
    for i in zi:
        temp = int(i)
        if 0<=temp<=255:
            temp = str(bin(temp))[2:].rjust(8,'0')
            to_bin += temp
        else:
            return False, to_bin
        #check if all 1 and all 0
        # if not (re.search(r'^[1]*$',temp) or re.search(r'^[0]*$',temp)):
        #     return False, to_bin
    #check if 0s after 1s
    if to_bin.rfind('1') == to_bin.index('0')-1:
        return True, to_bin
    else:
        return False, to_bin
def if_ip(ip):
    to_bin=""
    for i in ip:
        temp = int(i)
        if 0<=temp<=255:
            temp = str(bin(temp))[2:].rjust(8,'0')
            to_bin +=temp
        else:
            return False, to_bin
    return True, to_bin

if_zi, zi_bin = ifzi(zi)
if_ip1, ip1_bin = if_ip(ip1)
if_ip2, ip2_bin = if_ip(ip2)
if if_zi and if_ip1 and if_ip2:
    add_ip1 = bin(int(zi_bin, 2) & int(ip1_bin, 2))
    add_ip2 = bin(int(zi_bin, 2) & int(ip2_bin, 2))
    if add_ip1 == add_ip2:
        print(0)
    else:
        print(2)
else:
    print(1)