#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vb = vector<bool>;
using P = pair<ll, ll>;
template<typename T> using pq = priority_queue<T>;
template<typename T> using minpq = priority_queue<T, vector<T>, greater<T>>;
template<typename T, typename K> using ump = unordered_map<T, K>;
const ll dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const ll mod = 1000000007;
const ll inf = ll(1e9);
const ll e5 = ll(1e5);
const ll ll_inf = ll(1e9) * ll(1e9);

#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define repr(i, n) for (ll i = ll(n - 1); i >= 0; i--)
#define each(i, mp) for (auto &i : mp)
#define eb emplace_back
#define F first
#define S second
#define all(obj) (obj).begin(), (obj).end()

template<class T>
ostream &operator<<(ostream &out, const vector<T> &list) {
    ll n = list.size();
    rep(i, n) out << list[i] << ' ';
    return out;
}

template<class T>
istream &operator>>(istream &in, vector<T> &list) {
    ll n = list.size();
    rep(i, n) in >> list[i];
    return in;
}

template<class T>
ostream &operator<<(ostream &out, const vector<vector<T>> &list) {
    ll n = list.size();
    rep(i, n) out << list[i] << '\n';
    return out;
}

/* ------------- ANSWER ------------- */
/* ---------------------------------- */

void solve() {
    ll n;
    cin >> n;
    vector<string> ans;
    auto rec = [&](auto &&f, ll i, string now) -> void {
        if (i == n) {
            ans.eb(now);
            return;
        }
        f(f, i + 1, now + 'a');
        f(f, i + 1, now + 'b');
    };
    string now = "a";
    rec(rec, 1LL, now);
    cout << ans << '\n';
}

int main() {
#ifdef MY_DEBUG
    while (true) {
#endif
        solve();
#ifdef MY_DEBUG
    }
#endif
    return 0;
}