#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#define dump(val) cerr << __LINE__ << ":\t" << #val << " = " << (val) << endl

using namespace std;

typedef long long int lli;

int main() {
    lli H, W, N, K;
    cin >> H >> W >> N >> K;
    lli num = (H * W) % N;
    K %= N;
    cout << (num == K ? "YES" : "NO") << endl;
    return 0;
}