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

using namespace std;

int main()
{
	double borrowed, interest, prirust;
	long mpay;
	int years;
	

  while( true ) {
	scanf("%lf %ld %d %lf",&borrowed, &mpay, &years, &interest);
	if(borrowed == 0 && mpay==0&&years==0&&interest==0)
		break;
	int navrat = 0;
	prirust = borrowed*((interest/1200)+1)-borrowed;
	if(prirust >= mpay)
	{
		cout << "NO" << endl;
		continue;
	}
	for(int i =0;i<years*12;i++)
	{
		borrowed = borrowed*((interest/1200)+1);
		borrowed -= mpay;
		if(borrowed <=0)
		{
			navrat=1;
		}
	}
	if(navrat)
		cout << "YES" << endl;
	else
		cout << "NO" << endl;
	  
}
	

return 0;
}