LINQuistics

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public static void Main()
    {
        string input;
        var collections = new Dictionary<string, HashSet<string>>();
        while (!(input = Console.ReadLine()).Equals("exit"))
        {
            var inputSplit = input.Split('.');

            if (inputSplit.Length == 1)
            {
                int digit;
                bool isDigit = int.TryParse(inputSplit[0], out digit);
                if (isDigit)
                {
                    if (collections.Count > 0)
                    {
                        var methodNames = collections.Values
                            .First(m => m.Count == collections.Values.Max(c => c.Count))
                            .OrderBy(m => m.Length)
                            .Take(digit);
                        foreach (var method in methodNames)
                        {
                            Console.WriteLine($"* {method}");
                        }
                    }
                }
                else
                {
                    if (collections.ContainsKey(inputSplit[0]))
                    {
                        var methodNames = collections[inputSplit[0]]
                            .OrderByDescending(m => m.Length)
                            .ThenByDescending(m => m.Distinct().Count());
                        foreach (var methodName in methodNames)
                        {
                            Console.WriteLine($"* {methodName}");
                        }
                    }
                }
            }
            else
            {
                string collectionName = inputSplit[0];
                var methods = inputSplit.Skip(1);
                if (!collections.ContainsKey(collectionName))
                {
                    collections[collectionName] = new HashSet<string>();
                }
                foreach (var method in methods)
                {
                    var noBrackets = method.Trim('(', ')');
                    collections[collectionName].Add(noBrackets);
                }
            }
        }

        string[] lastLine = Console.ReadLine().Split();
        var searchedMethod = lastLine[0];
        var selection = lastLine[1];

        var result = collections
            .Where(c => c.Value.Contains(searchedMethod))
            .OrderByDescending(c => c.Value.Count)
            .ThenByDescending(c => c.Value.Min(m => m.Length));
        foreach (var collection in result)
        {
            Console.WriteLine(collection.Key);
            if (selection.Equals("all"))
            {
                var methods = collection.Value
                    .OrderByDescending(m => m.Length);
                foreach (var method in methods)
                {
                    Console.WriteLine($"* {method}");
                }
            }
        }
    }
}