题解 | #判断两个IP是否属于同一子网#

while True:
    try:
        mask,ip1,ip2=input().split('.'),input().split('.'),input().split('.')
        tag=0
        for i in [mask,ip1,ip2]:
            if len(i)!=4:
                tag=1
                break
            for j in i:
                if not j.isdigit:
                    tag=1
                    break
                else:

                    if int(j)<0 or int(j)>255:
                        tag=1
                        break
            if tag==1:
                break
        if tag==1:
            print(1)
            continue
        smask=''
        for i in mask:
            smask+=bin(int(i))[2:].zfill(8)
        if smask.find('0')-1==smask.rfind('1'):
            pass
        else:
            tag=1
        if tag==1:
            print(1)
            continue
        sip1=''
        for i in ip1:
            sip1+=bin(int(i))[2:].zfill(8)
        sip2=''
        for i in ip2:
            sip2+=bin(int(i))[2:].zfill(8)
        if int(smask,2) & int(sip1,2)==int(smask,2) & int(sip2,2):
            print(0)
        else:
            print(2)
        
                
    except:
        break