using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        string str= "aba";

        Dictionary<char,int> dictionary = new Dictionary<char,int>();

        foreach(char c in str)

        {

            if(dictionary.ContainsKey(c))

            {

                dictionary[c] ++;

            }

            else

            {

                dictionary.Add(c,1);

            }

        }

        foreach(var item in dictionary)

        {

            Console.WriteLine("Character : {0} and Occurences : {1}",item.Key,item.Value);

        }

    }

}