#!/usr/bin/env python
#coding:utf8
while True:
user = raw_input("請輸入用戶名:")
if user == ('isaac'):
password = raw_input('請輸入您的密碼:')
while True:
if password != ('123'):
print "密碼錯誤,請重試"
password = raw_input('請輸入您的密碼:')
if password == ('123'):
print "Hello %s" % user
break
break
else:
print "%s用戶不存在!" % user