using System;

public class Program

{

    public static void Main()

    {

        double tq,nq,mc,mhc;

        Console.WriteLine("ادخل طول قطر الدائرة:");

        tq=double.Parse(Console.ReadLine());

        nq=tq/2;

        mc=nq*nq*3.14159;

        mhc=tq*3.14159;

        Console.WriteLine("the nq is={0}",nq);

        Console.WriteLine("the mc is={0} and the mhc is={1}",mc,mhc);

    }

}