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

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

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

    int i;
    for (i = 1; i <= N * 12; i++) {
      X += X * (r / 12.0) / 100;
      X -= Y;
      if (X <= 0) {
        printf("YES\n");
        goto nextStep;
      }
    }

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

    nextStep:;
  }

  return 0;
}