How to choose a number among an arrangements of numbers

I've rewritten my answer to take the input from the user.

However, I can't write the rest of it any simpler than it already is.

What you have to remember here is that, when you remove an element from the list, the indices of the subsequent elements all move down by one. So, after each removal, instead of moving 3 elements to the right you only move 2 and, if there are not enough elements left, you have to wrap around to the beginning of the list again.

Also, when you get down to the last 2 elements, you have to make sure that the new index isn't outside the list altogether. Hence the need for the line:

if (index == li.Count) index = 0;

using System;

using System.Collections.Generic;

class Program

{

   static void Main()

   {

      Console.Write("How many numbers do you want to enter? : ");

      int n = int.Parse(Console.ReadLine());

      Console.WriteLine();

      List li = new List(n);

      for (int i = 0; i < n ; i++)

      {

         Console.Write("  Number {0} : ", i + 1);

         int num = int.Parse(Console.ReadLine());

         li.Add(num);

      }

      int last = GetLast(li);

      Console.WriteLine("\nThe last remaining nunmber is {0}", last);

      Console.ReadKey();

   }

   static int GetLast(List li)

   {

       int n = li.Count;       

       if (n == 0) throw new ArgumentException("List can't be empty");

       if (n == 1) return li[0]; 

       int min = li[0];

       int index = 0;

       for(int i = 1; i < n; i++)

       {

          if(li[i] < min)

          {

             min = li[i];

             index = i;

          }

       } 

       index += 3;

       while(li.Count > 1)

       {

          if (index >= li.Count)

          {  

             index -= li.Count;

             if (index == li.Count) index = 0;

          }

          li.RemoveAt(index);

          index += 2;      

       }

       return li[0];     

   }

}