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

using namespace std;

using ll = long long;
using ld = long double;

const int INF = (1 << 30) - 1;
const ll INF64 = ((ll)1 << 62) - 1;
const double PI = 3.1415926535897932384626433832795;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { -1, 0, 1, 0 };

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	int n;
	cin >> n;

	for (int i = 0; i < n; i++) {
		string str = "annnnnnnnnnnnnnnnnn";
		for (int j = 0; j < 17; j++) {
			if (i & 1 << j) {
				str[j + 1] = 'a';
			}
		}
		str += (i == n - 1 ? 'n' : 'a');
		cout << str << endl;
	}
	return 0;
}