#include <bits/stdc++.h>
using namespace std;
int mark[(10000000 >> 5) + 1];
void sieve() {
  register int i, j, k;
  (mark[1 >> 5] |= 1 << (1 & 31));
  int n = 10000000;
  for (i = 2; i <= n; i++) {
    if (!(mark[i >> 5] >> (i & 31) & 1)) {
      for (k = n / i, j = i * k; k >= i; k--, j -= i)
        (mark[j >> 5] |= 1 << (j & 31));
    }
  }
}
long long C(long long n, long long k) {
  if (k == 0) return 1;
  return (n * C(n - 1, k - 1)) / k;
}
long long modular_pow(long long budgetase, long long exponent, int modulus) {
  long long result = 1;
  while (exponent > 0) {
    if (exponent % 2 == 1) result = (result * budgetase) % modulus;
    exponent = exponent >> 1;
    budgetase = (budgetase * budgetase) % modulus;
  }
  return result;
}
long long binaryToDec(string number) {
  long long result = 0, pow = 1;
  for (int i = number.length() - 1; i >= 0; --i, pow <<= 1)
    result = (result + (number[i] - '0') * pow) % 1000003;
  return result;
}
long long GCD(long long a, long long b) { return b == 0 ? a : GCD(b, a % b); }
int main() {
  double d, h, v, e;
  cin >> d >> h >> v >> e;
  double r = d / 2;
  double area = 3.1415926535897932384626433832795 * r * r;
  if (e * area > v || fabs(e * area - v) < 0.0000000001) {
    cout << "NO" << endl;
    return 0;
  }
  double vol = 3.1415926535897932384626433832795 * r * r * h;
  double p = e * 3.1415926535897932384626433832795 * r * r;
  double dif = fabs(p - v);
  cout << "YES" << endl;
  cout << setprecision(12) << fixed << (double)vol / dif << endl;
}
