#include <bits/stdc++.h>
using namespace std;
const long double pi = acos(-1.0);
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long double d, h, v, e;
  cin >> d >> h >> v >> e;
  long double temp = (pi * d * d * e) / 4.0;
  if (temp >= v) {
    cout << "NO\n";
    return 0;
  }
  cout << "YES\n";
  temp = v - temp;
  temp = 1 / temp;
  temp = (temp * pi * d * d * h) / 4.0;
  cout << setprecision(10) << fixed << temp << "\n";
  return 0;
}
