#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, i = 0, j, k, count = 0, flag = 0, sum = 0, l, n, b[3005];
  double d, h, v, e, ans;
  scanf("%lf%lf%lf%lf", &d, &h, &v, &e);
  if (4 * v <= 3.14159265358979 * d * d * e)
    printf("NO\n");
  else {
    printf("YES\n");
    ans = 3.14159265358979 * d * d * h / (4 * v - 3.14159265358979 * d * d * e);
    printf("%lf\n", ans);
  }
  return 0;
}
