import Control.Applicative
import Text.Printf

main = do
  [aw,ab] <- fmap (read :: String -> Int) . words <$> getLine
  [bw,bb] <- fmap (read :: String -> Int) . words <$> getLine
  [c,d] <- fmap (read :: String -> Int) . words <$> getLine
  printf "%d\n" $ solve aw ab bw bb c d

solve aw ab bw bb 0 0 = aw
solve aw ab bw bb 0 d 
  | bw <= d = aw + bw
  | otherwise = aw + d
solve aw ab bw bb c d
  | ab >= c = solve aw (ab-c) bw (bb+c) 0 d
  | otherwise = solve (aw-rest) 0 (bw+rest) (bb+ab) 0 d
    where rest = c - ab