#include "bits/stdc++.h"

#define int long long

using namespace std;
using ll = long long;
using P = pair<ll, ll>;
const ll INF = (1LL << 61);
ll mod = 1000000007;


map<ll, ll> prime_factor(ll n) {
	map<ll, ll> ret;
	for (ll i = 2; i * i <= n; i++) {
		while (n % i == 0) {
			ret[i]++;
			n /= i;
		}
	}
	if (n != 1) ret[n] = 1;
	return ret;
}
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int X, A, Y, B; cin >> X >> A >> Y >> B;
	map<int, int>mp, mp2;
	mp = prime_factor(X);
	mp2 = prime_factor(Y);
	for (auto x : mp) {
		int now = x.second; now *= A;
		int now2 = mp2[x.first]; now2 *= B;
		if (now < now2) {
			cout << "No" << endl; return 0;
		}
	}
	cout << "Yes" << endl;
	return 0;
}