_username= 'haozheyu'

 _password= ''

 username = input("请输入用户：")

 password = input("请输入密码：")

 if _username == username and _password == password :

     print ("你输入对了")

 else :

     print("用户或密码错误 "

           "invalid username or password")

age_of_laochuanzhang = 56

age = int(input("请输入你的年龄："))

if age_of_laochuanzhang == age :

    print("yes, you got it.")

elif age_of_laochuanzhang > age:

    print("think smaller...")

else:

    print("think bigger!")