RepetitionInDictionary

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

namespace LetterRepetiton
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<char, int> letters = new Dictionary<char, int>();

            char[] inputChars = Console.ReadLine().ToArray();
            for (int i = 0; i < inputChars.Length; i++)
            {
                if (!letters.ContainsKey(inputChars[i]))
                {
                    letters.Add(inputChars[i], 0);
                }
                letters[inputChars[i]]++;
            }
            foreach (var item in letters.Keys)
            {
                Console.WriteLine($"{item} -> {letters[item]}");
            }
        }
    }
}