using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _21.DiffrentLettersInString
{
    class Program
    {
        static void Main(string[] args)
        {
            var text = "aaaaa bcd eeeff";

            char[] letters = new char[65536];

            for (int i = 0; i < text.Length; i++)
            {
                if (char.IsLetter(text[i]))
                {
                    letters[text[i]]++;
                }
            }

            for (int i = 0; i < letters.Length; i++)
            {
                if (letters[i]>0 && char.IsLetter((char)i))
                {
                    Console.WriteLine("{0} {1}",(char)i,(int)letters[i]);
                }
            }

        }
    }
}