('CID100287439', 1),Isovalericacid, cyclohexyl ester (6CI,7CI,8CI)
('CID100102737', 1),Isovalericacid, sec-butyl ester (6CI,8CI)
ldiff: defaultdict(<type 'list'>, {'CID100287439': [32], 'CID100102737': [27]})
f1: [32]
f2: [27]
c1: Counter({32: 1})
c2: Counter({27: 1})
The chosen was  ... CID100102737