using System;
using System.Globalization;
using System.Numerics;
public class Example
{
public static void Main()
{
BigInteger number = 999999999999999;
number = BigInteger.Pow(number, 3) * BigInteger.MinusOne;
NumberFormatInfo bigIntegerProvider = new NumberFormatInfo();
bigIntegerProvider.NegativeSign = "~";
Console.WriteLine(number.ToString(bigIntegerProvider));
}
}