('CID100022988', 1),Gluconicacid, manganese salt (2:1) (8CI)
('CID100193574', 1),Gluconicacid, 6-O-a-D-glucopyranosyl-, D- (8CI)
ldiff: defaultdict(<type 'list'>, {'CID100022988': [28], 'CID100193574': [35]})
f1: [28]
f2: [35]
c1: Counter({28: 1})
c2: Counter({35: 1})
The chosen was ... CID100022988