def display_fav_sub() -> str:
    """
    081
    Ask the user to type in their favourite school subject. Display it
    with “-” after each letter, e.g. S-p-a-n-i-s-h-.
    """
    fav_sub = input("Enter your favorite subject: ")
    [print(s, end="-") for s in fav_sub]
    return ""