import Control.Applicative
import Data.Bool (bool)

main :: IO ()
main = solve <$> f >>= putStrLn
  where
    f = map read <$> words <$> getLine

solve :: [Int] -> String
solve [a, b, c] = bool "No" "Yes" $ (==1) $ length $ filter (==0) $ [a-b, b-c, c-a]
