('CID100004856', 6),Piroxicam sodium salt
('CID100004856', 6),Apo-Piroxicam
('CID100004856', 6),Piroxicam
('CID100004856', 6),Piroxicam (JP15/USP/INN)
('CID100004856', 6),Piroxicam [USAN:BAN:INN:JAN]
('CID100004856', 6),piroxicam usp
('CID105745802', 5),Piroxicam Olamine
('CID105745802', 5),Piroxicam olamine (USAN)
('CID105745802', 5),Piroxicam monoethanolamine salt
('CID105745802', 5),Piroxicam olamine [USAN]
('CID105745802', 5),Piroxicam ethanolamine salt
ldiff: defaultdict(<type 'list'>, {'CID100004856': [12, 4, 0, 15, 19, 4], 'CID105745802': [8, 15, 22, 15, 18]})
f1: [12, 4, 0, 15, 19, 4]
f2: [8, 15, 22, 15, 18]
c1: Counter({4: 2, 0: 1, 19: 1, 12: 1, 15: 1})
c2: Counter({15: 2, 8: 1, 18: 1, 22: 1})
The chosen was ... CID100004856