static void Main(string[] args)
        {
            int a, b;
            MyCass mc = new MyCass();
            Console.Write("Enter First Line");
            a = Convert.ToInt32(Console.ReadLine());
            b = Convert.ToInt32(Console.ReadLine());


            Console.WriteLine(mc.Add(a,b));
            Console.WriteLine(mc.Dev(a,b));
            Console.WriteLine(mc.Mul(a,b));
            Console.WriteLine(mc.Sub(a,b));
            Console.ReadLine();
