import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import static java.lang.System.in; public class Main { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(in)); String[] inputs = reader.readLine().split(" "); long H = Long.parseLong(inputs[0]); long W = Long.parseLong(inputs[1]); long N = Long.parseLong(inputs[2]); long K = Long.parseLong(inputs[3]); if((H*W)%N == K%N) { System.out.println("YES"); } else { System.out.println("NO"); } } }