def topScore(L1, L2, sharedScoresO):
    """Find the best norm score between genes in L1 and L2. Return the index of
each and the score."""
    besti1 = 0
    besti2 = 0
    bestSc = -float('inf')
    for i1, gn1 in enumerate(L1):
        for i2, gn2 in enumerate(L2):
            sc = sharedScoresO.getScoreByEndNodes(gn1, gn2, 'rawSc')
            if sc != None and sc > bestSc:
                bestSc = sc
                besti1 = i1
                besti2 = i2
    return besti1, besti2, bestSc
