('CID100069897', 1),Oroticacid, 2-hydroxyethyl ester (7CI,8CI)
('CID100381087', 1),Oroticacid, 5-iodo- (8CI)
ldiff: defaultdict(<type 'list'>, {'CID100069897': [32], 'CID100381087': [15]})
f1: [32]
f2: [15]
c1: Counter({32: 1})
c2: Counter({15: 1})
The chosen was  ... CID100381087