using System;
using System.Collections.Generic;
class Program
{
	static void Main(string[] args)
	{
		string str = Console.ReadLine();
		int N = int.Parse(str);
		string w = "";
		string aaa = "abcdefghijklmopqrstuvwxyz";
		for(var i=0;i<N-1;i++){
			w = "";
			w += aaa.Substring(i%25,1);
			w += aaa.Substring((i/25/25/25/25/25)%25,1);
			w += aaa.Substring((i/25/25/25/25)%25,1);
			w += aaa.Substring((i/25/25/25)%25,1);
			w += aaa.Substring((i/25/25)%25,1);
			w += aaa.Substring((i/25)%25,1);
			w += aaa.Substring((i+1)%25,1);
			Console.WriteLine(w);
		}
		string w2 = aaa.Substring((N-1)%25,1) + "n";
		Console.WriteLine(w2);
	}
}