username = "xch"
i=3
userpassword = "888222666"
while True:
    if i>0:
        name = input("请输入用户名:")
        password = input("请输入密码:")
        i-=1
        if name == username and password == userpassword:
            print("登录成功!")
            break
        if username!=name:
            print("用户名错误！请重新输入")
            print("haiyou"+str(i)+"cijihui")
            continue
        if userpassword!=password:
            print("fhgtghghg6ij")
            print("haiyou"+str(i)+"cijihui")
    else:
        print("@xchdad")
        exit()
print("欢迎来到QQ!")