('CID100103363', 2),acrylic acid; 2-hydroxyaceticacid; titanium
('CID100103363', 2), 2-hydroxyaceticacid
('CID100000757', 1),Hydroxyaceticacid
ldiff: defaultdict(<type 'list'>, {'CID100103363': [26, 3], 'CID100000757': [0]})
f1: [26, 3]
f2: [0]
c1: Counter({26: 1, 3: 1})
c2: Counter({0: 1})
The chosen was  ... CID100000757