using System;

public class Hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        if (n == 1) { Console.WriteLine("n"); goto end; }
        Console.WriteLine("a");
        for (int i = 0; i < n -2; i++)
            Console.WriteLine("a" + getS(i) + "a");
        Console.WriteLine("an" );
        end:;
    }
    public static string getS(int n)
    {
        var a = "abcdefghijklmnopqrstuvwxyz";
        var ans = new char[4];
        for (int i = 0; i < 4; i++)
        {
            ans[i] = a[n % 26];
            n /= 26;
        }
        return new string(ans);
    }
}