#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define mod 1000000007ll
#define loop(i, n) for (int i = 0; i < n; i++)
#define all(v) v.begin(), v.end()
#define putout(a) cout << a << '\n'
#define Sum(v) accumulate(all(v), 0ll)

int main()
{
    ll N;
    cin >> N;
    vector<ll> num(18);
    loop(i, N - 1)
    {
        string now;
        num[0]++;
        ll j = 0;
        while (num[j] == 26)
        {
            num[j] = 0;
            num[j + 1]++;
            j++;
        }
        loop(j, 18) now += (char)('a' + num[j]);
        cout << "a" << now << "a" << endl;
    }
    putout("an");
    return 0;
}