#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;

    char c[21] = "xaaaax\n";
    for (int i = 0; i < n; i++) {
        int t = i;
        for (int j = 1; j <= 4; j++) {
            c[j] = t % 10 + 'a';
            t /= 10;
        }
        if (i == n - 1) c[5] = 'n';
        cout << c;
    }

    return 0;
}