using System;

​

public class Program

{

    public static void Main()

    {

        var p = new Program();

        var a = "abc";

        var b = p.convert(a);

        try

        {

            System.Console.WriteLine(b);

        }

        catch (Exception ex)

        {

            System.Console.WriteLine(ex);

        }

    }

​

    private int convert(String val)

    {

        try

        {

            return Int32.Parse(val);

        }

        catch (Exception ex)

        {

            throw new ArgumentException("no good", ex);

        }

    }

}