#include <bits/stdc++.h>
using namespace std;
long double r, h, v, e;
long double improvement;
long double vol;
int32_t main() {
  ios_base::sync_with_stdio(false);
  if (fopen("cf667a.in", "r")) {
    freopen("cf667a.in", "r", stdin);
    freopen("cf667a.out", "w", stdout);
  }
  cin >> r >> h >> v >> e;
  r /= 2.0;
  improvement = e * 4.0 * atan(1.0) * r * r;
  if (improvement > v) {
    cout << "NO\n";
    return 0;
  }
  cout << "YES\n";
  long double w = v - improvement;
  vol = r * r * 4.0 * atan(1.0) * h;
  cout << fixed << setprecision(20) << vol / w << '\n';
  return 0;
}
