('CID100074734', 1),Azelaicacid, dibenzyl ester (6CI,7CI,8CI)
('CID100246080', 1),Azelaicacid, bis(2-chloroethyl) ester (7CI,8CI)
ldiff: defaultdict(<type 'list'>, {'CID100074734': [30], 'CID100246080': [36]})
f1: [30]
f2: [36]
c1: Counter({30: 1})
c2: Counter({36: 1})
The chosen was ... CID100074734