def compare_txt(set1,
                set2
               ):
    """
        compare two sets of words
        return the ratio R of common words over the the length of the second set
        return also the rounded R
        (which is the floor of R if R is equally close to two integers,
        e.g the rounded 0.5 is 0)
    """
    common = set1.intersection(set2)
    ratio = 100 * len(common) / len(set2)
    return ratio, round(ratio)