#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const double mx = 1e4;
int main() {
  double d, h, v, e;
  cin >> d >> h >> v >> e;
  double nr = (4 * v) / (pi * d * d);
  if (nr > e) {
    cout << "YES";
    cout << endl;
    double n1 = h / (nr - e);
    if (n1 <= mx) cout << fixed << setprecision(6);
    cout << n1;
  } else {
    cout << "NO";
  }
  cout << endl;
  return 0;
}
