import java.util.Scanner;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author cteam063
 */
public class mortgage {

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        int x = scanner.nextInt();
        int y = scanner.nextInt();
        int n = scanner.nextInt();
        double r = scanner.nextDouble();
        while (!(x == 0 && y == 0 && n == 0 && Math.abs(r) < 0.000001)) {
            if (splaceni(x, r / 12, y, n)) {
                System.out.println("YES");
            } else {
                System.out.println("NO");
            }
            x = scanner.nextInt();
            y = scanner.nextInt();
            n = scanner.nextInt();
            r = scanner.nextDouble();
        }

    }

    public static boolean splaceni(double vstupnicastka, double urok, double splatka, int roku) {
        double novacastka = formulka(vstupnicastka, urok, splatka, roku * 12);
        if (novacastka <= 0) {
           return true;
        }

        return false;
        
    }

    public static double nextMonth(double castka, double urok, double splatka) {
        return castka * ((100 + urok) / 100) - splatka;
    }

    public static double formulka(double castka, double urok, double splatka, int mesicu) {
        final double r = (urok + 100.0) / 100.0;
//        return castka * Math.pow(r,mesicu) - splatka*((1-Math.pow(r, mesicu)) / (1-mesicu));
         return castka * Math.pow(r,mesicu) - splatka*((1-Math.pow(r, mesicu)) / (1-r));
    }
}