import Control.Applicative ((<$>))
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as B
import Data.List
import Data.Char (isSpace)

main :: IO ()
main = do
  solve <$> getl (readil B.readInt) >>= putStrLn

solve :: [Int] -> String
solve [h, w, n, k] = let r = h * w `mod` n
                     in if r == k || (r == 0 && n == k) then "YES" else "NO"

getl :: (ByteString -> a) -> IO a
getl f = f <$> B.getLine

readil :: Integral a =>  (ByteString -> Maybe (a, ByteString)) -> ByteString -> [a]
readil f = unfoldr g
  where
    g s = do
      (n, s') <- f s
      return (n, B.dropWhile isSpace s')