('CID100074637', 1),Diphenylaceticacid chloride
('CID100018289', 1),2-Amino-2,2-diphenylaceticacid
ldiff: defaultdict(<type 'list'>, {'CID100074637': [9], 'CID100018289': [12]})
f1: [9]
f2: [12]
c1: Counter({9: 1})
c2: Counter({12: 1})
The chosen was ... CID100074637