('CID100191989', 2),Dithiobis(n-ethylmaleimide)
('CID100191989', 2),Dithiobis(N-ethylmaleimide)
('CID100194813', 2),Captopril N-ethylmaleimide Sulfone
('CID100194813', 2),Captopril N-ethylmaleimide sulfone
ldiff: defaultdict(<type 'list'>, {'CID100194813': [18, 18], 'CID100191989': [11, 11]})
f1: [11, 11]
f2: [18, 18]
c1: Counter({11: 2})
c2: Counter({18: 2})
The chosen was ... CID100191989