using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<int> originalList = new List<int> { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 };

​

        var oddIndexedItems = originalList.Where((item, index) => index % 2 == 0);

        var evenIndexedItems = originalList.Where((item, index) => index % 2 != 0);

​

        var reorderedList = oddIndexedItems.Concat(evenIndexedItems).ToList();

​

        Console.WriteLine("Order: " + string.Join(" ", reorderedList));

    }

}