('CID100446590', 2),TETRA(IMIDAZOLE)DIAQUACOPPER (II)
('CID100446590', 2),TETRA(IMIDAZOLE)DIAQUACOPPER (II)
('CID105288624', 1),TETRA(IMIDAZOLE)DIAQUACOPPER (II)
ldiff: defaultdict(<type 'list'>, {'CID100446590': [1, 1], 'CID105288624': [1]})
f1: [1, 1]
f2: [1]
c1: Counter({1: 2})
c2: Counter({1: 1})
The chosen was ... CID100446590