/* -*- coding: utf-8 -*-
 *
 * 1723.cc:  No.1723 [Cherry 3rd Tune *] Dead on - yukicoder
 */

#include<cstdio>
#include<cstring>
#include<vector>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_P = 1000000 + 100;

/* typedef */

typedef long long ll;
typedef vector<int> vi;
typedef pair<ll,int> pli;
typedef vector<pli> vpli;

/* global variables */

bool primes[MAX_P + 1];

/* subroutines */

int gen_primes(int maxp, vi &pnums) {
  memset(primes, true, sizeof(primes));
  primes[0] = primes[1] = false;

  int p;
  for (p = 2; p * p <= maxp; p++)
    if (primes[p]) {
      pnums.push_back(p);
      for (int q = p * p; q <= maxp; q += p) primes[q] = false;
    }
  for (; p <= maxp; p++)
    if (primes[p]) pnums.push_back(p);
  return (int)pnums.size();
}

bool prime_decomp(ll n, vi &pnums, vpli& pds) {
  pds.clear();

  int pn = pnums.size();
  for (int i = 0; i < pn; i++) {
    int pi = pnums[i];
    if (pi * pi > n) {
      if (n > 1) pds.push_back(pli(n, 1));
      return true;
    }

    if (n % pi == 0) {
      int fi = 0;
      while (n % pi == 0) n /= pi, fi++;
      pds.push_back(pli(pi, fi));
    }
  }
  return false;
}

/* main */

int main() {
  ll x, a, y, b;
  scanf("%lld%lld%lld%lld", &x, &a, &y, &b);

  vi pnums;
  gen_primes(MAX_P, pnums);

  vpli xpds, ypds;
  prime_decomp(x, pnums, xpds);
  prime_decomp(y, pnums, ypds);

  vpli::iterator vit = xpds.begin();
  for (auto ypf: ypds) {
    while (vit != xpds.end() && vit->first < ypf.first) vit++;
    if (vit == xpds.end() || vit->first > ypf.first ||
	vit->second * a < ypf.second * b) {
      puts("No");
      return 0;
    }
  }

  puts("Yes");
  return 0;
}