public static void D()
{
Console.WriteLine("(D) Using BigToLong method.");
BigNum bigNumC1 = new BigNum(35L);
long? num1 = bigNumC1.BigToLong();
Console.WriteLine(num1);
BigNum bigNumC2 = new BigNum(9223372036854775807L);
long? num2 = bigNumC2.BigToLong();
Console.WriteLine(num2);
BigNum bigNumD = new BigNum();
bigNumD.Complement();
long?num3 = bigNumD.BigToLong();
Console.WriteLine(num3);
Console.WriteLine();
}
