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

int main()
{
	long int b,c,j;
	double i;
int k;
	
	double a,d;
	scanf("%lf %ld %ld %lf",&a,&b,&c,&d);
while(a!=0&&b!=0&&c!=0&&d!=0)
{

	j=c*12;	
/*	for (i=0;i<j;i++)
	{
	a+=(a/100*(d/12));
	
	}
*/
	d=d/12;
	
if ((a*pow((d/(100)+1),(double)(j-1)))<=(b*j)) printf("YES\n");else printf("NO\n");
scanf("%lf %ld %ld %lf",&a,&b,&c,&d);
}
return 0;
}