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

int main(void){
int rok, i;
long double suma, splatka;
double urok;
scanf("%Lf %Lf %d %.2lf", &suma,&splatka,&rok,&urok);
while(suma == 0.00 && splatka  == 0.00 && rok == 0 && urok == 0.00){
for(i = 0; i < (rok*12); i++){
	suma = suma + (int)suma*((urok/12)/100) - splatka;
}
if (suma <= 0) printf("YES\n");
else printf("NO\n");
scanf("%Lf %Lf %d %lf", &suma,&splatka,&rok,&urok);
}
return 0;
}