import qualified Data.IntMap.Strict as M
import Data.List

main = getContents >>= print . sushi . map read . tail . words

sushi = fst . M.findMax . foldl dp (M.singleton 0 True)

dp im v = M.insertWith (||) (fst (M.findMax im)) True im'
 where im' = M.map (const False) $ M.mapKeys (+v) (M.filter id im)