using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;
using System.Text;

public class Program
{

    public void Proc()
    {
        int len = int.Parse(Reader.ReadLine());

        StringBuilder ans = new StringBuilder();
        for (int i = 0; i < len; i++) {
            string tmp = i.ToString().PadLeft(18, '0');
            tmp = string.Join("", tmp.Select(a => (char)('a' + int.Parse(a.ToString()))));
            tmp = "a" + tmp + "a";
            ans.AppendLine(tmp);
        }
        Console.Write(ans.ToString());
    }


    public class Reader
    {
        static StringReader sr;
        public static bool IsDebug = false;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (sr == null)
                {
                    sr = new StringReader(InputText.Trim());
                }
                return sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        private static string InputText = @"


7






";
    }

    public static void Main(string[] args)
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}