C# throw文

using System;

namespace exception8
{
internal class Program
{
static void Main(string[] args)
{
try
{
try
{
int[] a = new int[3];

                a[0] = 1;
                a[5] = 2;
            }
            catch (Exception)
            {
                Console.WriteLine("最初の捕捉");
                throw;
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("外側の捕捉");
            Console.WriteLine(e.Message);
        }
    }
}

}