def METHOD_NAME() -> Optional[int]:
    times = []
    for slot_index in range(3):
        save_path = get_save_path(slot_index + 1)
        save_data = open_save_file(save_path)
        if save_data is not None:
            time_of_save = datetime.datetime.strptime(
                save_data["time"],
                TIME_FORMAT,
            )
            times.append((slot_index, time_of_save))
    if len(times) > 0:
        s = max(times, key=itemgetter(1))
        return s[0]
    else:
        return None