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

#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
#define all(x) (x).begin(), (x).end()

using ll = long long; 

int main(void) {
    cin.tie(0); ios::sync_with_stdio(false);
    ll n; cin >> n;
    string s(21, 'a');
    rep(i, n-1) {
        ll tmp = i / 2;
        if (i % 2 == 0) 
            rep(j, s.length()-1) 
                s[s.length()-1-j] = 'a' + 1 + tmp % 25, tmp /= 25;
        cout << s << endl;
        reverse(all(s));
    }
    cout << s[0] << 'n' << endl;
    return 0;
}