print "1. Login"
print "2. Register"
print "3. View user"

pilihan = raw_input("Pilih opsi: [1,2,3]: ")

if pilihan == "1":
    username = raw_input("username: ")
    password = raw_input("password: ")
    try:
        f = open("user.txt", 'r')
        for word in f.read().split():
            if username == word and password == word:
                print "Welcome %s" % username
            else:
                print "User tidak ditemukan"
    except IOError:
        print "file tidak ada"
elif pilihan == "2":
    f = open("user.txt", 'a+')
    username = raw_input("masukan username: ")
    f.write(username + " ")
    password = raw_input("masukan password: ")
    f.write(password + " ")
elif pilihan == "3":
    pass
else:
    print "Pilihan Anda tidak ada"