using System;

using System.Collections.Generic;

public class Program

{

    public static readonly char[] HEX_SYMBOLS = new char[] 

            {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',

             'a', 'b', 'c', 'd', 'e', 'f'};

    public static string NumToHex(int num) {

        if (num == 0)

            return "0";

        var rest = (uint)num;

        var res = new List<char>();

        while (rest > 0)

        {

            var digit = rest % 16;

            rest /= 16;

            res.Add(HEX_SYMBOLS[digit]);

        }

        res.Reverse();

        return string.Join("", res);

    }

    public static void Main()

    {

        Console.WriteLine("UniLecs");

        // tests

        Console.WriteLine(NumToHex(26)); // 1A

        Console.WriteLine(NumToHex(-1)); // ffffffff

    }

}