#include <iostream>
#include <math.h>

//#include <fstream>

using namespace std;


int main()
{
    double r;
    unsigned long X, Y, N;

    while (X || Y || N || r) {

        cin >> X >> Y >> N >> r;

        double num = 0;
        for (unsigned long i = 1; i <= N * 12; i++) {
            num += pow((1 + r/100 / 12), (N * 12)- i);
        }

        if ((X * pow((1 + r/100 / 12), (N * 12))) - Y*num <= 0) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }

        // double total;





    }

    return 0;
}