#define _USE_MATH_DEFINES
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string>
#include<iostream>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include <sstream>
#include<iomanip>
#include <ctype.h>
#include <fstream>
#include <cassert>
//#include <bits/stdc++.h>
using namespace std;

//#include<bits/stdc++.h>


	
int main() {
	string p = "aaaaaaaaaaaaaaaaaaaa";
	int n;
	cin >> n;
	
	for (int i = 0; i < 50; i++) {
		cout << p << endl;
		p[1]++;
		for (int i = 1; i <= 18; i++) {
			if (p[i] > 'z') {
				p[i + 1]++;
				p[i] = 'a';
			}
		}
	}

	return 0;
}