object Main {
  def main(args: Array[String]) {
    val sc = new java.util.Scanner(System.in)
    val H, W, N, K = sc.nextLong

    val m = (H * W) % N
    val isLose = if (m == 0) K == N else m == K
    println(if (isLose) "YES" else "NO")
  }
}