#include <bits/stdc++.h>
using namespace std;
int main() {
  double d, h, v, e, vol;
  double pi = 4 * (atan(1));
  cin >> d >> h >> v >> e;
  if ((pi * d * d * e) / 4 >= v)
    cout << "NO" << endl;
  else {
    cout << "YES\n";
    vol = v - ((pi * d * d * e) / 4);
    cout << fixed << setprecision(8) << (pi * h * d * d) / (4 * vol);
  }
}
