#include <iostream>
#include <string>

using namespace std;

bool calc(double X, double Y, double N, double r)
{
for( int i = 0; i < N*12; i++)
{
	X += X*(r/100/12);
	X-=Y;
	if(X<=0){
		return true;
	}
	
}

return false;
}


int main(void){

double X, Y, N, r;


while(1) {
		cin >> X;
		cin >> Y;
		cin >> N;
		cin >> r;
		if ( X == 0 && Y == 0 && N == 0 && r == 0)
			return 0;
		if(calc(X,Y,N,r))
			cout << "YES" << endl;
		else
			cout << "NO" << endl;

	} 

return 0;

}