drop :: Int -> [A] -> [A]
-- testing 360 combinations of argument values
-- pruning with 4/7 rules
-- 2 candidates of size 1
-- 3 candidates of size 2
-- 4 candidates of size 3
-- 6 candidates of size 4
-- 8 candidates of size 5
-- 13 candidates of size 6
-- 24 candidates of size 7
-- tested 39 candidates
drop 0 xs  =  xs
drop x []  =  []
drop x (y:xs)  =  drop (x - 1) xs

take :: Int -> [A] -> [A]
-- testing 153 combinations of argument values
-- pruning with 4/7 rules
-- 2 candidates of size 1
-- 3 candidates of size 2
-- 4 candidates of size 3
-- 6 candidates of size 4
-- 8 candidates of size 5
-- 13 candidates of size 6
-- 24 candidates of size 7
-- 31 candidates of size 8
-- 59 candidates of size 9
-- tested 111 candidates
take 0 xs  =  []
take x []  =  []
take x (y:xs)  =  y:take (x - 1) xs