#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pdd pair<double, double>
#define F first
#define S second
#define all(x) x.begin(), x.end()

using namespace std;


signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    vector<string> base;
    for (int i = 1; i <= 50; i++)
    {
        string s = "aa";
        s[0] += (i - 1) / 2;
        s[1] += i / 2;
        base.emplace_back(s);
    }
    vector<string> sol = base;
    while (sol.size() <= 5000)
    {
        vector<string> nxt;
        for (int i = 0; i < 50; i += 2)
        {
            for (auto s : sol)
                nxt.emplace_back(base[i] + s);
            nxt.emplace_back(base[i + 1] + sol.back());
            reverse(all(sol));
        }
        sol.swap(nxt);
    }
    int N;
    cin >> N;
    for (int i = 0; i < N; i++)
        cout << sol[i] << '\n';
}