#include <stdio.h>
#include <iostream>

int main()
{
	int y, n;
	double x, r;
	
	while (1)
	{
		std::cin >> x;
		scanf("%d %d", &y, &n);
		std::cin >> r;
		
		if (x == 0 && y == 0 && n == 0 && r == 0)
		{
			break;
		}
		
		int cycleCount = n * 12;
		
		if ((y * cycleCount) < x)
		{
			printf("NO\n");
			continue;
		}
		
		double lastX = 0;
		for (int i = 1; i <= cycleCount; i++)
		{
			
			x += (x * (r / 1200)) - y;
			
			if (x <= 0.0)
			{
				break;
			}
			
			if (i != 1)
			{
				if (x > lastX)
				{
					break;
				}
			}
			
			lastX = x;
		}
		
		printf((x <= 0.0) ? "YES\n" : "NO\n");
	}
	
	return 0;
}