#include <cstdlib>
#include <cstdio>
#include <cmath>

using namespace std;

int main(){
	while(1){
		int debt=0;
		int payment=0;
		int years=0;
		float percentage=0;
		scanf("%d %d %d %f", &debt, &payment, &years, &percentage);
		if(debt==0 && payment==0 && years==0 && percentage==0){
			break;
		}
		//printf("%f %f %f\n",percentage,percentage/100,percentage/100/12);
		for(int i=0;i<(years*12);i++){
			//printf("debt_s=%d\n",debt);
			//printf("payment=%d\n",payment);
			//printf("debt*((percentage/100)/12)=%f\n",debt*((percentage/100)/12));
			debt+=debt*((percentage/100)/12);
			debt-=payment;
			//printf("debt_e=%d\n",debt);
		}
		if(debt>0){
			printf("NO\n");
		}
		else{
			printf("YES\n");
		}
	}
	return 0;
}