#include <algorithm>
#include <cstdio>
#include <iostream>
#include <string>
#include <vector>
#include <map>
#define rep(i, n) for (int i=0; i<n; ++i)
#define FOR(i, a, b) for (int i=a; i<b; ++i)
#define pb(x) push_back(x)
#define ll long long
#define ul unsigned long long
#define dbg(x) cout  << #x << " : " << (x) << endl
#define out(x) cout << (x)
#define outl(x) cout << (x) << endl
#define int(n); int n; cin >> n;
#define long(n); long long n; cin >> n;
#define dbl(f); double f; cin >> f;
#define s(s); string s; cin >> s;
#define into(a, n) for (int i = 0; i < n; ++i) cin >> a[i]
using namespace std;

const int inf =1500000000;
int main () {
   ll h, w, n, k, l;
   cin >> h >> w >> n >> k;
   l = h*w%n;
   outl(l == k || (l == 0 && n == k) ?  "YES" : "NO");
}