#include <iostream>
#include <algorithm>
using namespace std;

long long ps(long long n, long long k)
{
	long long c = 0;
	while (n % k == 0) {
		c++;
		n /= k;
	}
	return c;
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	long long x, y, a, b; cin >> x >> a >> y >> b;
	for (long long i = 2; i * i <= y; i++) {
		if (y % i != 0) continue;
		if (ps(x, i) * a < ps(y, i) * b) {
			cout << "No\n";
			return 0;
		}
		while (y % i == 0)
			y /= i;
	}
	if (y > 1 && a * ps(x, y) < b) 
		cout << "No\n";
	else
		cout << "Yes\n";
	return 0;
}