Parse string with special Negative Sign to BigInteger in CSharp

  /* w  ww  . j  a v  a  2 s. c om*/
  
  
  
using System;
using System.Numerics;
using System.Globalization;
public class Class1
{
   public static void Main()
   {
        NumberFormatInfo fmt = new NumberFormatInfo();
        fmt.NegativeSign = "~";
        
        BigInteger number = BigInteger.Parse("~9999999999999", fmt);
        Console.WriteLine(number.ToString(fmt));
        Console.WriteLine(number);
   }
}