#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000007
#define INF 1000000000 //(int)1e9
#define LLINF 2000000000000000000 //(ll)2e18
#define PI  3.1415926536

#define SIZE 1000

int main(){
    ll h,w,n,k;
    
    cin >> h >> w >> n >> k;
    
    if(h*w%n == k%n){
        puts("YES");
    }else{
        puts("NO");
    }
    
    return 0;
}