import           Data.Function
import           Data.List

combinations :: Int -> [a] -> [[a]]
combinations 0 _  = [ [] ]
combinations n xs = [ y:ys | y:xs' <- tails xs
                           , ys <- combinations (n-1) xs']


names = ["clock", "painting", "radio", "vase", "book", "computer"]
vals = [175, 90, 20, 50, 10, 200]
weights = [10, 9, 4, 2, 1, 20]

goods = [(names !! i,vals !! i,weights !! i) | i<-[0..5]]

combs = foldl1 (++) [combinations i goods | i<-[1..6]]

less = filter (\xs -> sum [w|(_,_,w)<-xs] <= 20) combs

ans = maximumBy (on compare (\r -> sum [v|(_,v,_)<-r])) less