#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <tuple>
#include <bitset>

#define rep(i,n) for(i=0; i<n; ++i)
#define in(a) cin >> a
#define out(a,b) cout << a << b
using namespace std;
using lint = long long;

bool is_prime(lint n){
    if(n==2||n==3)    return true;
    if(n<2||n%2==0) return false;
    bool f=true;
    for(lint i=3; i*i<=n; i+=2){
        if(n%i==0){
            f=false; break;
        }
    }
    return f;
}

vector<pair<lint, lint>> prime_factorize(int n){
    vector<pair<lint, lint>> prime_factors; lint p=2, cnt=0;
    while(n>1){
        if(n%p!=0){
            if(cnt!=0){
                prime_factors.push_back(make_pair(p, cnt)); cnt=0;
            }
            do{p++;}while(!is_prime(p));
        }
        else{
            n/=p; cnt++;
        }
    }
    prime_factors.push_back(make_pair(p, cnt));
    return prime_factors;
}

int main(void){
    // lint i, j;
    lint n, m;
    lint x, a, y, b;
    in(x);
    in(a);
    in(y);
    in(b);
    vector<pair<lint, lint>> primes_x=prime_factorize(x);
    vector<pair<lint, lint>> primes_y=prime_factorize(y);
    lint x_i=primes_x.size(), y_i=primes_y.size();
    bool covered=true;
    
    lint i, j=0;
    rep(i,y_i){
        lint n_x, p_x=0, n_y, p_y;
        tie(p_y, n_y)=primes_y[i];
        while(p_x!=p_y){
            if(j>x_i-1){
                covered=false;
                break;
            }
            tie(p_x, n_x)=primes_x[j];
            j++;
        }
        if((n_x*a)<(n_y*b)){
            covered=false;
            break;
        }
        if(!covered)    break;
    }
    
    covered? out("Yes", endl):out("No", endl);
    return 0;
}