using System;

using System.Linq;

using System.Numerics;

public class Program

{

    public static void Main()

    {

        string piStr = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679";

​

        BigInteger pi = BigInteger.Parse(piStr.Replace(".", ""));

​

        BigInteger value = pi * 789789347928325;

​

        string result = value.ToString().Insert(16, ".");

​

        Console.WriteLine(result);

    }

}