import Data.List

main = do
 [r,g,b] <- map read . words <$> getLine
 print (rgb r g b)

rgb r g b = head . until p f . sort $ [r,g,b]
 where
  p [x,y,z] = z - x < 3
  f [x,y,z] = sort [x+1,y,z-2]