from typing import List
import re


def split_stop_keep_word_string(input_string: str) -> List[str]:
    """Breaks stop and keepword string inputs into lists of words.

    :param input_string: A string of words input by the user.
    :return: A list of the user's string broken up into words.
    """

    input_lines = input_string.split("\n")

    # A list of all words delimited by commas, spaces, and newlines
    input_words = [word
                   for line in input_lines
                   for word in re.split('[, ]', line.strip())
                   if word != '']

    return input_words