('CID100000743', 3),Glutaricacid (8CI)
('CID100000743', 3),Glutaricacid, ammonium salt (8CI)
('CID100000743', 3),Glutaricacid, monosodium salt (8CI)
('CID100000043', 2),Glutaricacid, 2-hydroxy-, disodium salt (7CI)
('CID100000043', 2),Glutaricacid, 2-hydroxy-, L- (8CI)
ldiff: defaultdict(<type 'list'>, {'CID100000743': [6, 21, 23], 'CID100000043': [33, 22]})
f1: [6, 21, 23]
f2: [33, 22]
c1: Counter({21: 1, 6: 1, 23: 1})
c2: Counter({33: 1, 22: 1})
The chosen was ... CID100000743