#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>
#include <bitset>
#include <cassert>

using namespace std;
using ll = long long;
const long long INF = 1LL << 60;
const long long MOD = 1000000007;


int main() {

    long long int H, W, N, K;
    cin >> H >> W >> N >> K;

    long long int T = ((H * W) % N == 0) ? N : (H * W) % N;

    if (T == K) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }


    return 0;
}