#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <string.h>

using namespace std;

int main()
{
	for(;;)
	{
		
		long long dlh, spl, rok;
		float urok;
		int pocitadlo = 0;
		scanf("%lld%lld%lld%f", &dlh, &spl, &rok, &urok);
		if (!dlh && !spl && !rok &&!urok)
			break;

		long long prev_dlh = dlh;

		urok /= 12;
		urok /= 100;
		for(;;)
		{
			double plus = dlh * urok;
			dlh = dlh + plus - spl;
			if (prev_dlh <= dlh && pocitadlo % 12 == 0 && pocitadlo > 0)
			{
				printf ("NO\n");
				goto next;
			}
			pocitadlo++;	

			if (dlh <= 0)	
				break;
		}

		if (pocitadlo<=rok*12-1)
			printf("YES\n");
		else printf("NO\n");
		
		next:;
	}

	return 0;
}