#include <bits/stdc++.h>
using namespace std;

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

int main() {
	fast_io();
	long long x, a, y, b;
	cin >> x >> a >> y >> b;
	map<long long, int> pf_x, pf_y;
	for (long long i = 2; i * i <= x; i++) {
		while (x % i == 0) {
			pf_x[i]++;
			x /= i;
		}
	}
	if (x > 1) {
		pf_x[x]++;
	}
	for (long long i = 2; i * i <= y; i++) {
		while (y % i == 0) {
			pf_y[i]++;
			y /= i;
		}
	}
	if (y > 1) {
		pf_y[y]++;
	}
	for (auto [k, v] : pf_y) {
		if (pf_x[k] * a < v * b) {
			cout << "No\n";
			return 0;
		}
	}
	cout << "Yes\n";
}