#include <cstdio>
#include <cstdlib>

double g_R;
int g_Y;
double g_X;

double fce(int m){
    if(m) return ( fce(m-1) * (1+g_R) - g_Y );
    else return ( g_X * (1+g_R) - g_Y );
}

int main () {

    int y, n;
    double r, x;
    while( scanf("%lf%d%d%lf",&x,&y,&n,&r), x!=0 ){
	g_R = r/1200;
	n *= 12;
	g_X = x;
	g_Y = y;
	x = fce(n-1);
//	printf("x: %.0lf...",x);
	if( x > 0 ) printf("NO\n");
	else printf("YES\n");
	//
	//
//	x = g_X;
//	for(int i=0;i<n;i++)
//	   x = x + g_R * x - g_Y;
//	printf("x: %.0lf...",x);
//	if( x > 0 ) printf("NO\n");
//	else printf("YES\n");
	
    }

}