using System;

class KorenNa4Decimale {
  static void Main() {
    double x1, x2, a;
    Console.WriteLine("Unesi a");
    a = double.Parse(Console.ReadLine());
    // pretpostavljamo da je a > 0 i to ne proveravamo
    x2 = a / 2;
    do {
      x1 = x2;
      x2 = 0.5*(x1 + a/x1);
    } while(Math.Abs(x2 - x1) >= 0.0001);
    Console.WriteLine("Koren je {0}", x2);
  }
}