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


using namespace std;


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

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

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

        long double R = (1 + r/100 / 12); // monthly interest rate
        long double M = N * 12;

        long double qm = X*pow(R, M) - Y*(R*(pow(R, M-1) - 1)/(R - 1) + 1);

        if (qm <= 0) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }

        /*
        cin >> X >> Y >> N >> r;

        double num = 0;
        //cout << (1 + r/100)*(pow(1 + r/100 / 12, (N * 12) - 1)) / ((1 + r/100 / 12) - 1);
        //cout << pow((1 + r/100 / 12), (N * 12)) - 1;

        double cache = 1;
        double num1 = 0;
        for (unsigned long i = 1; i <= N * 12; i++) {
            num += pow((1 + r/100 / 12), (N * 12)- i);
            cache *= (1 + r/100/12);
            num1 += cache;
            num1 -= Y;
            if (num1 <= 0) {
                break;
            }
            //num += pow((1 + r/100 / 12), (N * 12)- i);
        }
        cout << num1 << " " << num << endl;

        if (num1 <= 0) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }

        // double total;

        */



    }

    return 0;
}