using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        string str = "In the end this is not the end";

        var dict2 = groupCount(str, 2);

        Console.WriteLine("Group Of 2:");

        foreach ( string k in dict2.Keys ) {

            Console.WriteLine("Key: \"{0}\", Count: {1}", k, dict2[k]);

        }

        Console.WriteLine();

        var dict3 = groupCount(str, 3);

        Console.WriteLine("Group Of 3:");

        foreach ( string k in dict3.Keys ) {

            Console.WriteLine("Key: \"{0}\", Count: {1}", k, dict3[k]);

        }

        Console.WriteLine();

    }

    public static Dictionary<string,int> groupCount(string str, int groupCount) 

    {

        string[] tokens = str.Split(new char[] { ' ' });

        var dict = new Dictionary<string,int>();

        for ( int i = 0; i < tokens.Length - (groupCount-1); i++ ) 

        {

            string key = "";

            for ( int j = 0; j < groupCount; j++ ) 

            {

                key += tokens[i+j] + " ";

            }

            key = key.Substring(0, key.Length-1);

            if ( dict.ContainsKey(key) ) {

                dict[key]++;

            } else {

                dict[key] = 1;

            }

        }

        return dict;

    }

}