{-# LANGUAGE PartialTypeSignatures #-}
module Main (main) where

import Data.Bool
import qualified Data.ByteString.Char8 as C8
import qualified Data.Char as C
import qualified Data.List as L

main :: IO ()
main = readInts >>= output . solve

solve :: [Int] -> _
solve [defT,atkT,defA,atkA] = takahashi <= aoki
  where
    takahashi = steps atkT defA
    aoki = steps atkA defT

    steps atk = length . L.unfoldr (\v -> if v <= 0 then Nothing else Just (v, v-atk))

output :: _ -> IO ()
output = print . bool No Yes

data YesNo = Yes | No
  deriving Show

-- utils
readInts :: IO [Int]
readInts = L.unfoldr (C8.readInt . C8.dropWhile C.isSpace) <$> C8.getLine