Combinations

import Data.List(sort, sortBy)

-- генерирует все сочетания
findSolution l found len current
    | found == len = [current]
    | length l < len - found = []
    | otherwise = (findSolution (tail l) (succ found) len (current ++ [head l])) ++ (findSolution (tail l) found len current)

-- обертка над верхней функцией
solve l = concat [findSolution (sort l) 0 len [] | len <- [1..(length l)]]

-- замена в списке всех элементов a на b
replace [] _ _ = []
replace (x:xs) a b
    | x == a = (b:(replace xs a b))
    | otherwise = (x:(replace xs a b))

-- лексикографический порядок
lexOrder :: [Int] -> [Int] -> Ordering
lexOrder [] [] = EQ
lexOrder [] (x:xs) = LT
lexOrder (x:xs) [] = GT
lexOrder (x:xs) (y:ys)
    | x == y = lexOrder xs ys
    | x < y = LT
    | otherwise = GT

-- лексикографическая сортировка
lexSort = sortBy lexOrder

main = do
    input <- getLine -- считывание
    print $ lexSort $ solve $ (read ("[" ++ (replace input ' ' ',') ++ "]") :: [Int]) -- вывод ответа