#include <bits/stdc++.h>
using namespace std;
template <class T>
bool smin(T &_x, T &_y) {
  return _x <= _y ? false : ((_x = _y), true);
}
template <class T>
bool smax(T &_x, T &_y) {
  return _x >= _y ? false : ((_x = _y), true);
}
const int maxn = 1e5 + 5;
const long double pi = 3.141592653589;
const int mod = 1e9 + 7;
int n;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long double r, h, v, e;
  cin >> r >> h >> v >> e;
  r /= 2;
  long double s = r * r * pi;
  if (v / s - e < 0) {
    cout << "NO" << endl;
    return 0;
  }
  cout << "YES\n" << h / (v / s - e) << endl;
}
