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

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

for(i = 0; i < rok*12; i++)
	suma = suma + suma*((urok/12)/100) - splatka;

if (suma <= 0) printf("YES\n");
else printf("NO\n");
scanf("%d %d %d %f", &suma,&splatka,&rok,&urok);
}

	return 0;
}