#include <bits/stdc++.h>
using namespace std;
const long double PI = 3.141592653589793;
long long fpow(long long base, long long power) {
  long long result = 1;
  while (power > 0) {
    if (power % 2 == 1) {
      result = (result * base);
    }
    base = (base * base);
    power /= 2;
  }
  return result;
}
int main() {
  long double d, h, v, e;
  cin >> d >> h >> v >> e;
  long double num = (0.25 * PI * d * d * h);
  long double den = v - (0.25 * PI * d * d * e);
  if (den < 0) {
    cout << "NO\n";
    return 0;
  } else if (v < e) {
    cout << "NO\n";
    return 0;
  } else {
    cout << "YES\n";
    long double ans = num / den;
    cout << fixed;
    cout << setprecision(12) << ans << "\n";
    return 0;
  }
}
