#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ld long double


const int N = 5005 + 9, mod = 998244353;
const ll OO = 1e9;

int n;
set<string> vis;
vector<string> v;

bool solve(string cur, int d) {
    if (d == 5000) {
        return true;
    }
    v.push_back(cur);
    for (int i = 0; i < cur.size(); ++i) {
        for (char j = 'a'; j <= 'z'; ++j) {
            if (cur[i] != j) {
                auto nxt = cur;
                nxt[i] = j;
                if (vis.find(nxt) == vis.end()) {
                    for (int k = 0; k < cur.size(); ++k) {
                        for (char l = 'a'; l <= 'z'; ++l) {
                            auto tmp = cur;
                            tmp[k] = l;
                            vis.insert(tmp);
                        }
                    }
                    return solve(nxt, d + 1);
                }
            }
        }
    }
    return false;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    vis.insert(string(10, 'a'));
    solve(string(10, 'a'), 0);
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cout << v[i] << '\n';
    }
    return 0;
}