import Data.List

main = do
 vs <- sort . map read . words <$> getLine
 print (ita vs)

ita vs@[v1,v2,v3,v4] = minimum $ do
 x <- [1 .. v4]
 y <- [x .. v4]
 z <- [y .. v4]
 return $ sum $ map (f [x,y,z]) vs

f _ 0 = 0
f [] v = 10000
f (w:ws) v
 | w > v = f ws v
 | otherwise = min (f (w:ws) (v-w) + 1) (f ws v)