#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1000000007;
using P = pair<int,int>;
#define rep(i, n) for(int i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()

int main(){
    ll x,a,b,y;
    cin >> x >> a >> y >> b;
    for(int i=2;i<=1000000;i++){
        int cnt1 = 0, cnt2 = 0;
        while(!(x%i)){
            cnt1++;
            x /= i;
        }
        while(!(y%i)){
            cnt2++;
            y /= i;
        }
        if(cnt1*a<cnt2*b){
            cout << "No" << endl;
            return 0;
        }
    }
    if(y==1 || (x==y && a>=b)) cout << "Yes" << endl;
    else cout << "No" << endl;
    return 0;
}