#include <bits/stdc++.h>
using namespace std;
using vi = vector<int>;
using pi = pair<int, int>;
using ll = long long int;
template <typename T1, typename T2, typename T3>
T1 modpow(T1 _a, T2 p, T3 mod) {
  assert(p >= 0);
  ll ret = 1, a = _a;
  if (a < 0) {
    a %= mod;
    a += mod;
  }
  if (a >= mod) {
    a %= mod;
  }
  for (; p > 0; p /= 2) {
    if (p & 1) ret = ret * a % mod;
    a = a * a % mod;
  }
  return ret;
}
constexpr int dx[] = {-1, 0, 1, 0, 1, 1, -1, -1};
constexpr int dy[] = {0, -1, 0, 1, 1, -1, 1, -1};
constexpr auto PI = 3.14159265358979323846L;
constexpr auto oo = numeric_limits<int>::max() / 2 - 2;
constexpr auto eps = 1e-6;
constexpr auto mod = 1000000007;
constexpr int mx = -1;
int d, h, v, e;
int main() {
  scanf("%d %d %d %d", &d, &h, &v, &e);
  long double evol = PI * d * d * e / 4;
  ;
  if (evol >= v - eps) {
    printf("NO\n");
  } else {
    long double r = d / 2.0;
    long double vol = PI * r * r * h;
    long double t = vol / (v - evol);
    cout << "YES\n" << fixed << setprecision(4) << t << endl;
  }
  return 0;
}
