Try to parse string to BigInteger in CSharp

using System;/*  ww w  .  ja v a  2  s  . c om*/
using System.Numerics;

public class Example
{
   public static void Main()
   {

        BigInteger number1, number2;
        bool succeeded1 = BigInteger.TryParse("-999999999999999999", out number1);
        bool succeeded2 = BigInteger.TryParse("8888888888888888888", out number2);
   }
}