import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) {
		BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
		try {
			String[] line = read.readLine().split(" ");
			long[] num = new long[4];
			for (int i = 0; i < 4; ++i) {
				num[i] = Long.parseLong(line[i]);
			}
			long total = num[0] * num[1];

			if (total % num[2] == num[3]) {
				System.out.println("YES");
			} else if (total % num[2] == 0) {
				if (num[2] == num[3]) {
					System.out.println("YES");
				} else {
					System.out.println("NO");
				}
			} else {
				System.out.println("NO");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}