#include<stdio.h>

int main()
{
	int X, Y, N;
	double c;

	while(scanf("%d %d %d %lf", &X, &Y, &N, &c),N)
	{
		c/= 100.0;
		double dpt = X;
		for(int i=1; i<N*12;i++)
		{
			dpt = dpt * (1 + c/12.0) - Y;
			if (dpt < 0)
				break;
		}
		if (dpt < 0)
			printf("YES\n");
		else
			printf("NO\n");
	}
	
	return 0;
}