using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Set 1");  //Original set from posed problem

        ShowMissing(new List<int>() {12,4,13,9,5,10,14,2,6,1,11,8,7});

        Console.WriteLine("Set 2");  //Just sme random numbers that don't start at 1 and are missing 2 values from the order

        ShowMissing(new List<int>() {20,23,25,31,26,28,29,22,27,21});

        Console.WriteLine("Set 3");  //same as Set 1 but numbers start 80 higher.

        ShowMissing(new List<int>() {92,84,93,89,85,90,94,82,86,81,91,88,87});  }

    public static void ShowMissing(List<int> inList)

    {

        inList.Sort();

        int current = inList[0];

        foreach (int n in inList)

        {

            if(current != n)

            {

                Console.WriteLine("  Missing " + current);

                current++;

            }

            current++;

        } 

    }

}