#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 %lf", &suma,&splatka,&rok,&urok);
while(suma != 0 && splatka  != 0 && rok != 0 && urok != 0){

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("%Lf %Lf %d %lf", &suma,&splatka,&rok,&urok);
}
return 0;
}