('CID124838540', 7),PPG-17-Buteth-17
('CID124838540', 7),PPG-24-Buteth-27
('CID124838540', 7),PPG-28-Buteth-35
('CID124838540', 7),PPG-2-Buteth-3
('CID124838540', 7),PPG-33-Buteth-45
('CID124838540', 7),PPG-36-Buteth-36
('CID124838540', 7),PPG-3-Buteth-5
('CID100006473', 5),Butethal
('CID100006473', 5),butethal, monosodium salt
('CID100006473', 5),Butethal Sodium
('CID100006473', 5),Concord brand of butethal
('CID100006473', 5),Butethal sodium
ldiff: defaultdict(<type 'list'>, {'CID100006473': [0, 17, 7, 17, 7], 'CID124838540': [8, 8, 8, 6, 8, 8, 6]})
f1: [8, 8, 8, 6, 8, 8, 6]
f2: [0, 17, 7, 17, 7]
c1: Counter({8: 5, 6: 2})
c2: Counter({17: 2, 7: 2, 0: 1})
The chosen was  ... CID100006473