#include <cstdio>
#include <cmath>
#include <cstring>
#include <cctype>
#include <cstdlib>
#include <climits>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <list>
#include <algorithm>
#include <string>

using namespace std;

#define FOR(i,m,n) for (int i = m; i < n; i++)
#define EPS (1E-8)

int main() {
  int x, y, n;
  double r, curr; float rr; 
  while(1) {
    scanf("%d%d%d%f", &x, &y, &n, &rr);
    r = rr; 
    if (x == 0 && y == 0 && n == 0 && r == 0) break;
    curr = x;
    int b = 0;
    r = 1 + r / 1200;
    double r12 = 1;
    for (int i = 0; i < 12; i++) r12 *= r;
    
    if (n < 500) {
      for (int i = 0; i < n && !b; i++) {
        curr = curr * r12 - y * (1 - r12) / (1 - r);
        if (curr <= EPS) {
          printf("YES\n");
          b = 1;
          break;
        }
      }
      if (!b) {
        printf("NO\n"); 
      }
    }
    else {
      double s = x * (r - 1);
      if (s > y) {
         printf("NO\n");
      }
      else {
        printf("YES\n");
      }
    }
  }

  return 0;
}
/*for (int m = 0; m < 12; m++) {
        curr *= (1 + r / 12 / 100);
        curr -= y;
        if (curr <= EPS) {
          printf("YES\n");
          b = 1;
          break;
}
}*/