with open("user.txt") as f:
    A = [str(x) for x in f.read().split()]

with open("password.txt") as j:
    B = [str(x) for x in j.read().split()]

d={}
lenA=len(A)
for i in range(lenA):
    d[A[i]]=B[i]
a='user selection'

def enterpassword(i):
    username=input('enter username : ')
    password=input('enter password : ')
    if (username in d and d["username"]=="password"):
        print(a)
    else:
        while i<3:
            print("invalid login")
            enterpassword(i+1)
        while i>=3:
            newpw=password
            d[username]=newpw


enterpassword(i)