#include <bits/stdc++.h>

using namespace std;
using ll = long long;
const int mod = 998244353;

struct mint {
    ll x; // typedef long long ll;
    mint(ll x = 0) : x((x % mod + mod) % mod) {}

    mint operator-() const { return mint(-x); }

    mint &operator+=(const mint a) {
        if ((x += a.x) >= mod) x -= mod;
        return *this;
    }

    mint &operator-=(const mint a) {
        if ((x += mod - a.x) >= mod) x -= mod;
        return *this;
    }

    mint &operator*=(const mint a) {
        (x *= a.x) %= mod;
        return *this;
    }

    mint operator+(const mint a) const { return mint(*this) += a; }

    mint operator-(const mint a) const { return mint(*this) -= a; }

    mint operator*(const mint a) const { return mint(*this) *= a; }

    mint pow(ll t) const {
        if (!t) return 1;
        mint a = pow(t >> 1);
        a *= a;
        if (t & 1) a *= *this;
        return a;
    }

    // for prime mod
    mint inv() const { return pow(mod - 2); }

    mint &operator/=(const mint a) { return *this *= a.inv(); }

    mint operator/(const mint a) const { return mint(*this) /= a; }
};

istream &operator>>(istream &is, const mint &a) { return is >> a.x; }

ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }

int main() {
    int n;
    cin >> n;
    map<int, bool> m;
    for (int i = 0; i < (1 << n); ++i) {
        if (m[i])continue;
        string s = "";
        char c = 'a' + bitset<10>(i).count();
        int x = 0;
        for (int j = 0; j < n; ++j) {
            if (i & (1 << j))s = c-- + s;
            else {
                s = 'a' + s;
                x += pow(2, j);
            }
        }
        m[x] = true;
        cout << s << endl;

        return 0;

}
