#include<stdio.h>
#include<stdlib.h>
#include<string.h>

int main(void){
int rok, i;
double suma, urok, splatka;
scanf("%lf %lf %d %lf", &suma,&splatka,&rok,&urok);
while(suma && splatka && rok && urok){

for(i = 0; i < (rok*12); i++){
	suma = suma + (int)suma*((urok/12)/100);
}
if (suma <= splatka*rok*12) printf("YES\n");
else printf("NO\n");
scanf("%lf %lf %d %lf", &suma,&splatka,&rok,&urok);
}
return 0;
}