public static void Main()
    {
        int        a  = 10;
        int        b  = 20;
        MathsClass mc = new MathsClass();

        Console.WriteLine("Product ", mc.Multiply(a, b));
    }
    private void CallMultiply()
    {
        MathsClass mc = new MathsClass();

        mc.Multiply(21, 2);
    }