using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        //Console.WriteLine("Hello World");

        string str = "I am .net developer developer developer and I am developing .net app app";

        string[] arr = str.Split(' ');

        Dictionary<string,int> output = new Dictionary<string,int>();

        foreach( var i in arr)

        {

            string word = i;

            if(output.ContainsKey(word))

            {

                output[word]+=1;

            }

            else

            {

                output.Add(word,1);

            }

        }

        var order = output.OrderByDescending(x=>x.Value);

        foreach( var pair in order)

        {

            Console.WriteLine("{0}:{1}",pair.Key,pair.Value);

        }

    }

}