('CID100000985', 2),2,2-D2-Palmiticacid
('CID100000985', 2),Palmiticacid (7CI,8CI)
('CID120227484', 1), Palmiticacid, iron(3+) salt (8CI)
ldiff: defaultdict(<type 'list'>, {'CID120227484': [22], 'CID100000985': [7, 10]})
f1: [7, 10]
f2: [22]
c1: Counter({10: 1, 7: 1})
c2: Counter({22: 1})
The chosen was ... CID100000985