EnterNumbers

using System;
using System.Collections.Generic;

public class EnterNumbers
{
    public static int? ReadNumber(ref int start, ref int end)
    {
        Console.Write("Enter an integer [{0}..{1}] inclusive: ", start, end);
        try
        {
            int n = int.Parse(Console.ReadLine());

            if (n < start || n > end) throw new ArgumentOutOfRangeException();
            if (n == end)
            {
                end = n - 1;
                return n;
            }

            if (n + 1 <= end)
            {
                start = n + 1;
                return n;
            }

            return null;
        }
        catch (ArgumentOutOfRangeException)
        {
            return null;
        }
        catch (ArgumentNullException)
        {
            return null;
        }
        catch (FormatException)
        {
            return null;
        }
        catch (OverflowException)
        {
            return null;
        }
    }

    public static void Main(string[] args)
    {
        int start = 1;
        int end = 100;
        int count = 0;
        List<int> numList = new List<int>();

        while (count < 10)
        {
            int? n = ReadNumber(ref start, ref end);

            if (n.HasValue)
            {
                count++;
                numList.Add((int)n);
            }

            if (start > end)
            {
                Console.WriteLine("No more integers to choose from. Range length is zero.");
                break;
            }
        }

        Console.WriteLine("Finnished. {0} integers have been chosen", count);
        string implode = string.Join(", ", numList.ToArray());
        Console.WriteLine(implode);
    }
}