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


int main(void){

int X,Y,N;
double r, dx,qn,eps;

while (1){
	scanf("%d %d %d %lf", &X, &Y, &N, &r);
	if (X==0&&Y==0&&N==0&&r==0) break;
	N*=12;
	r/=12;
	r/=100;	
	qn=pow((r+1),N);
	dx=(X*qn)-Y*((qn-1)/r);
	eps=X*qn*10E-8;
	if (dx<eps) printf("YES\n");
	else printf("NO\n");
}

return 0;
}