('CID100135814', 2),Z-Pro-prolinal
('CID100135814', 2),Z-PRO-PROLINAL
('CID100004350', 1),Z-Pro-prolinal
ldiff: defaultdict(<type 'list'>, {'CID100135814': [0, 0], 'CID100004350': [0]})
f1: [0, 0]
f2: [0]
c1: Counter({0: 2})
c2: Counter({0: 1})
The chosen was ... CID100135814