using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var result = Enumerable.Range(1, 20).SelectMany(x => x.ToString()).GroupBy(x => x).ToDictionary(x => x.Key, x => x.Count());

        foreach(var item in result)

            Console.WriteLine($"Number of {item.Key} : {item.Value}");

    }

}