def move(text, i, j):
    """Move operation.

    move position X to position Y means that the letter which is at
    index X should be removed from the string, then inserted such that it
    ends up at index Y.

    """
    chars = [t for t in text]
    letter = chars[i]
    chars.pop(i)
    chars.insert(j, letter)
    return "".join(chars)