#!./usr/bin/env python
# -*- coding: utf-8 -*-
# Date: 2019/8/21
# Author: sun

a_file = open('A.txt', 'r')
b_file = open('B.txt', 'r')
c_file = open('C.txt', 'w')

b_phone = []
for phone in b_file.readlines():
    b_phone.append(phone.strip('\n'))

for phone in a_file.readlines():
    if phone.strip('\n') not in b_phone:
        c_file.write(phone)

a_file.close()
b_file.close()
c_file.close()