#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

int main() {
  ll X,A,Y,B;cin>>X>>A>>Y>>B;
  vector<ll> vec(0);
  ll y=Y;
  for(ll i=2;i<=sqrt(Y);i++) {
    if(y%i==0) {
        vec.push_back(i);
        while(y%i==0) {
            y/=i;
        }
    }
  }
  if(y>1) {
      vec.push_back(y);
  }
  ll N=vec.size();
  vector<vector<ll>> note(2,vector<ll> (N,0));
  for(ll i=0;i<N;i++) {
      ll count=0;
      ll y=0;
      while(X%vec[i]==0) {
          X/=vec[i];
          count++;
      }
      while(Y%vec[i]==0) {
          Y/=vec[i];
          y++;
      }
      note[0][i]=count;
      note[1][i]=y;
  }

  for(ll i=0;i<N;i++) {
      if(note[0][i]*A<note[1][i]*B) {
          cout<<"No"<<endl;
          return 0;
      }
  }
  cout<<"Yes"<<endl;
}