('CID100066217', 2),Decanoicacid, 2-ethyl-2-[[(1-oxodecyl)oxy]methyl]-1,3-propanediyl ester (9CI)
('CID100066217', 2), Decanoicacid, triester with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol (6CI,7CI,8CI)
('CID100009555', 2),Decanoicacid, nonadecafluoro- (6CI,7CI,8CI,9CI)
('CID100009555', 2),Decanoicacid, nonadecafluoro-, ammonium salt (8CI,9CI)
ldiff: defaultdict(<type 'list'>, {'CID100009555': [35, 42], 'CID100066217': [65, 72]})
f1: [65, 72]
f2: [35, 42]
c1: Counter({72: 1, 65: 1})
c2: Counter({42: 1, 35: 1})
The chosen was  ... CID100009555