#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

map<ll, ll> prime_factorization(ll n){
  map<ll, ll> ans;
  ll a = 2;
  while(n >= a*a){
    if(n % a == 0){
      ans[a]++;
      n /= a;
    }else{
      a++;
    }
  }
  ans[n]++;

  return ans;
}

int main() {
  ll x, a;
  cin >> x >> a;
  ll y, b;
  cin >> y >> b;
  if(y == 1) {
    cout << "Yes" << endl;
    return 0;
  }
  auto xp = prime_factorization(x);
  auto yp = prime_factorization(y);
  bool ans = false;
  for(auto [p, q] : yp) {
    q *= b;
    ll xq = xp[p];
    xq *= a;
    if(xq < q) {
      ans = true;
      break;
    }
  }
  if(!ans) cout << "Yes" << endl;
  else cout << "No" << endl;
  return 0;
}