leg :: Int -> Int -> Int
leg a b | a < b = 1
        | b < a = -1
        | a == b = 0

(*.) :: (Double,Double) -> (Double,Double) -> (Double,Double)
(a1,b1) *. (a2,b2) = (a1*a2, b1*b2)

lista22 [] = []
lista22 [_] = []
lista22 (_:x:xs) = x : lista22 xs

suma1 = sum(map(\i -> 2/((i^2)+1))[1..2000])
iloczyn1 = product(map(\i -> sin i * cos i)[20..45])

sumTree Null = 0
sumTree (Leaf a) = a
sumTree (Node a left right) = a + sumTree left + sumTree right