#include <stdio.h>
#include <math.h>

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

  while (1) {
    scanf ("%lf %d %d %lf", &X, &Y, &N, &r);
    if (X == 0 || Y == 0 || N == 0)
      break;

    int i;
    for (i = 1; i <= N * 12; i++) {
      X += X * (r / 12.0) / 100;
      /*X = floor(X);*/
      X -= Y;
      /*printf("%lf %d\n", X, Y);*/
    }

    if (X > 0) printf("NO\n");
    else printf("YES\n");
  }

  return 0;
}