#include <bits/stdc++.h>
using namespace std;
int main() {
  const double pi = 3.14159265358979323846;
  double r, h, v, e;
  cin >> r >> h >> v >> e;
  double x = pi;
  x = pi * r * r * h / 4;
  double t = x / (v - pi * r * r * e / 4);
  if (t < 0 || t > 10000)
    cout << "NO";
  else {
    cout << "YES" << endl;
    cout << t;
  }
}
