#include <bits/stdc++.h>
using namespace std;
long long int M = 1e9 + 7;
int sum_digit(int x) {
  int sum = 0;
  while (x > 0) {
    sum += x % 10;
    x /= 10;
  }
  return sum;
}
int reverse_num(int n) {
  int tmp = n, ans = 0, r;
  while (tmp > 0) {
    r = tmp % 10;
    ans = ans * 10 + r;
    tmp /= 10;
  }
  return ans;
}
long long int factorial(long long int n) {
  long long int i, ans = 1;
  for (i = n; i > 1; i--) {
    ans *= i;
  }
  return ans;
}
long long int gcd(long long int num1, long long int num2) {
  long long int a, b, r;
  a = num1;
  b = num2;
  r = a % b;
  while (r > 0) {
    a = b;
    b = r;
    r = a % b;
  }
  return b;
}
long long int lcm(long long int num1, long long int num2) {
  return (num1 * num2) / gcd(num1, num2);
}
bool prime(long long int n) {
  if (n < 2) return false;
  for (long long int i = 2; i <= sqrt(n); i++) {
    if (n % i == 0) return false;
  }
  return true;
}
bool vowel(char ch) {
  ch = tolower(ch);
  if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u')
    return true;
  return false;
}
void solve() {
  double d, h, v, e;
  cin >> d >> h >> v >> e;
  double r = d / 2;
  double v_in = 2 * acos(0) * r * r * h;
  double L = 0, R = 1e4 + 10;
  double ans = 0;
  while (L < R) {
    double t = L + (R - L) / 2;
    double dif = (v_in + 2 * acos(0) * r * r * e * t) - v * t;
    if (abs(dif) < 1e-4) {
      ans = t;
      break;
    }
    if (dif < 0)
      R = t;
    else
      L = t;
  }
  if (ans != 0) {
    cout << "YES\n";
    cout << setprecision(12) << fixed << ans << endl;
  } else
    cout << "NO\n";
}
int main() {
  solve();
  return 0;
}
