def splitIntoBigTrainMiniVal(file_names):  # using Narihira's method
    """Split the content as in the Narihira paper and put into three lists."""
    train = []
    val = []
    test = []
    for ind, fn in enumerate(file_names):
        if ind % 5 == 0:  # take ID 0 and 5 from 0-9 (20%)
            test.append(fn)
        elif ind % 100 == 6:  # take ID 6 from 0-99 (1%)
            val.append(fn)
        else:
            train.append(fn)  # take ID 1,2,3,4,7,8,9, 11-14, 16-19, ... (79%)
    return train, val, test