('CID100445626', 2),DIOXOTHIOMOLYBDENUM(VI) ION
('CID100445626', 2),DIOXOTHIOMOLYBDENUM(VI) ION
('CID106365228', 1),DIOXOTHIOMOLYBDENUM(VI) ION
ldiff: defaultdict(<type 'list'>, {'CID106365228': [1], 'CID100445626': [1, 1]})
f1: [1, 1]
f2: [1]
c1: Counter({1: 2})
c2: Counter({1: 1})
The chosen was ... CID100445626