class Four {
  public static void main(String[] args) {
    double n = Double.parseDouble( args[0] ); 
    System.out.println( Four.sqrt( n ) + " squared is equal to " + n ); 
  } 
  static double sqrt(double n) {
    double low = 0, high = n, guess = (high + low) / 2; 
    while (high - low > 1E-12) {
      if (guess * guess < n) low = guess; 
      else if (guess * guess > n) high = guess; 
      else break; 
      guess = (high + low) / 2; 
    } 
    return guess; 
  }
}