from typing import List


def string_of_single_to_list_of_ints(input_string: str) -> List[int]:
    """
    Split a string on `split_string` and return a list of integers

    :param input_string: String to split
    :return: List of integers
    """
    list_of_ints = list(map(int, input_string))
    return list_of_ints