from typing import List


def replace_with_wildcard(word: str, indices: List[int],
                          wildcard: str = '\uFFFF'):
    """Replace char at a certain index with a wildcard

    word : str
        A string

    indices : List[int]
        List of indicies. len(word)<max(indices)

    wildcard : str
        An unicode char that is not actually used by any natural language,
          or the text that you analyzing, e.g. U+FFFE or U+FFFF
          See https://en.wikipedia.org/wiki/Specials_(Unicode_block)

    Example:
    --------
        word = 'ABCDE'
        replace_with_wildcard(s, [2, 4])
    """
    return ''.join([wildcard if i in indices else c
                    for i, c in enumerate(word)])