Indexer in C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace IndexerProgram
{
    class Program
    {
        static void Main(string[] args)
        { int choice = 5;
            IndexerOfSecond ios = new IndexerOfSecond();
            int currentIndex = 0;
            do
            {
                Console.WriteLine("Choose one of the following\n");
                Console.WriteLine("1. Enter value\n2.Get element\n3.Exit\n");
                Console.WriteLine("Write Now:");
                int ch = int.Parse(Console.ReadLine());

                if(ch == 1)
                {
                    Console.WriteLine("\nEnter the value to store : ");
                    
                    int val = int.Parse(Console.ReadLine());
                    ios[currentIndex] = new Second(val);
                    currentIndex++;
                }
                if(ch == 2)
                {
                    Console.WriteLine("\nEnter the Index to get : ");
                    int index = int.Parse(Console.ReadLine());
                    (ios[index]).printVal();
                }
                if (ch > 2 || ch < 1)
                {
                    Environment.Exit(0);
                }
                Console.WriteLine("\n Do you want more operations . Press 5\n");
                choice = int.Parse(Console.ReadLine());
            } while (choice == 5);
        }
    }

    class Second
    {
        int val;
        public Second ()
            {
            val=0;
            }
        public Second(int x)
        {
            val = x;
        }
        public void printVal()
        {
            
            Console.WriteLine("\nValue is : " + val + "\n");
        }
    }

    class IndexerOfSecond
    {
        private readonly Second[] SecondObjArray = new Second[10];
        public static int size = 10;
        
        public Second this[int index]{
            get
            {
                if(index > (size-1) && index < 0)
                {
                    return new Second();
                }
                else
                {
                    return SecondObjArray[index];
                }
            }
            set
            {
                if (index <= 9 && index >-1)
                {
                    SecondObjArray[index] = value;
                    
                }
            }
            }


    }
}