def _f_p_r_lcs(llcs, m, n):
    """
    Computes the LCS-based F-measure score
    Source: http://research.microsoft.com/en-us/um/people/cyl/download/papers/
    rouge-working-note-v1.3.1.pdf

    Args:
      llcs: Length of LCS
      m: number of words in reference summary
      n: number of words in candidate summary

    Returns:
      Float. LCS-based F-measure score
    """
    r_lcs = llcs / m
    p_lcs = llcs / n
    beta = p_lcs / (r_lcs + 1e-12)
    num = (1 + (beta**2)) * r_lcs * p_lcs
    denom = r_lcs + ((beta**2) * p_lcs)
    f_lcs = num / (denom + 1e-12)
    return f_lcs, p_lcs, r_lcs