def measure_relative(S):
    """Calculate the "measure-relative" score as defined in the paper

    Args:
        S (List[List[int]]): accuracy counts as defined in the paper

    Returns:
        score (float): measure-relative score
    """
    denom = S[0][0] + S[1][1] + S[0][1] + S[1][0]
    if denom == 0:
        return 0
    return (S[0][1] - S[1][0]) / denom