def score_formula(f1, f2):
    """
    Binary strict version
    """
    score = -1000
    if len(f1) != len(f2) or not f1 or not f2:
        return -1000
    for piece1 in f1:
        if piece1 not in f2:
            break
        elif f1[piece1] != f2[piece1]:
            break
    else:
        score = 1000
    return score
