#include <algorithm>
#include <cmath>
#include <cstring>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <unordered_map>
#include <vector>

using namespace std;
using ll = long long;

char nextCh(char ch) {
    if (ch == 'z') {
        return 'a';
    } else {
        return (char)(ch + 1);
    }
}

string S(int n) {
    string ret = "";
    while (n > 0) {
        ret += (char)(n % 26 + 'a');
        n /= 26;
    }
    return ret;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    map<char, int> count;
    int n;
    cin >> n;
    char ch = 'a';
    for (int i = 0; i < n; i++) {
        if (i == n - 1) {
            cout << ch << S(count[ch]) << 'n' << endl;
        } else {
            cout << ch << S(count[ch]) << nextCh(ch) << endl;
            count[ch]++;
            ch = nextCh(ch);
        }
    }

    return 0;
}