#include <stdio.h>

int main(void){
    int W, H;
    long long int N, K;
    scanf("%d %d %lld %lld", &W, &H, &N, &K);
    if((W*H)%K==0 && (W*H)>=K){
        printf("YES\n");
    }else{
        printf("NO\n");
    }
    return 0;
}