#include <bits/stdc++.h>
#define pb push_back
#define sz(x) (int)X.size()
#define all(x) x.begin(), x.end()
#define f first
#define s second
using namespace std;
using ll = long long;
using pii = pair <int, int>;
const int N = 2e5 + 5;
int main() {
	ios :: sync_with_stdio(false);
	cin.tie(nullptr);
	int n;
	cin >> n;
	string cur = "aaaa";
	map <string, int> was, wass[4];
	for (int k = 0; k < 4; ++k) {
		string t = cur.substr(0, k) + cur.substr(k, 4 - k - 1);
		if (wass[k].count(t) == 0) 
			wass[k][t] = 0;
	}
	for (int i = 0; i < n; ++i) {
		cout << cur << '\n';
		string ok = cur;
		was[cur] = 1;
		string nxt = "-1";
		for (int j = 0; j < 4; ++j) {
			char x = cur[j];
			for (char c = 'a'; c <= 'z'; ++c) {
				if (c == x)
					continue;
				cur[j] = c;
				if (was[cur])
					continue;
				bool bad = 0;
				for (int k = 0; k < 4; ++k) {
					string t = cur.substr(0, k) + cur.substr(k + 1, 4 - k - 1);
					if (wass[k].count(t) && wass[k][t] < i) {
						bad = 1;
						break;
					}
				}
				if (!bad) {
					nxt = cur;
					break;
				}
			}
			if (nxt != "-1")
				break;
			cur[j] = x;
		}
		assert(nxt != "-1");
		cur = nxt;
		for (int k = 0; k < 4; ++k) {
			string t = cur.substr(0, k) + cur.substr(k + 1, 4 - k - 1);
			if (!wass[k].count(t)) {
				wass[k][t] = i + 1;
			}
		}
	}
	return 0;
}