using System;

using System.Linq;

​

​

public class Program

{

    public static void Main()

    {

        var k = @"System

System.Collection.Generic

System.Generic

System.Linq

System.Linq.Collection.Generic";

        foreach (var item in k.Split('\n').OrderBy(x => x.Count(l => l == '.')))

            Console.WriteLine(item);

    }

}