import Control.Applicative
import Control.Monad
import qualified Data.ByteString.Char8 as B
import Data.Maybe (fromJust)
import Text.Printf
import Debug.Trace

readInts :: B.ByteString -> [Integer]
readInts = map (fst . fromJust . B.readInteger) . B.words

getInts :: IO [Integer]
getInts = liftM readInts B.getLine

main = do
  [h,w,n,k] <- getInts
  let ans = if h*w `mod` n == k `mod` n then "YES" else "NO"
    in putStrLn ans