#include <stdio.h>

int main() {
	long long int h, w, n, k;

	scanf("%lld %lld %lld %lld", &h, &w, &n, &k);

	if (((h * w) % n == 0 ? n : (h * w) % n) == k) printf("YES\n");
	else printf("NO\n");

	return 0;
}