known_users = ["Alice","Bob","Clair","Dan","Emma","Fred","Georgia","Harry"]

while True:
    print("Hi!My Name Is Travis")
    name = input("What Is Your Name?:").strip().capitalize()

    if name in known_users:
        print("Hello {}!".format(name))
        remove = input("Would You Like To Be Removed From The System(y/n)?:")
        if remove == "y":
            known_users.remove(name)
            print("you are removed {}!".format(name))
            print("here is the list of users: {}".format(known_users))
        break
    else:
        print("Hmmm, I Dont Think I Have Met You Yet {}!".format(name))
        add_me = input("Would You Like To Be Added In The System(y/n)?!:").strip().lower()
        if add_me == "y":
            known_users.append(name)
            print("you are successfully added {}!".format(name))
            print("here is the list of users: {}".format(known_users))
        break