('five'@5,'four'@4,'one'@1,'three'@3,'two'@2)
('five'@5,'one'@1,'three'@3)
('A'@'a','B'@'ab','C'@'abc','D'@'abcd','E'@'abcde','F'@'abcdef')
('A'@'a','C'@'abc','E'@'abcde')
