#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll mod=998244353;
ll inf=1009999999999999990;
int main(){
    ll n;
    cin >> n;
    map<string,ll>memo;
    memo["a"]++;
    cout << "a" << endl;
    for (ll i = 0; i < n-1; i++)
    {
        while (1)
        {
            string s="a";
            for (ll j = 0; j < 18; j++)
            {
                char c='a';
                c+=rand()%26;
                s.push_back(c);
            }
            if (i==n-2)
            {
                s.push_back('n');
            }else{
                s.push_back('a');
            }
            if (memo[s]==0)
            {
                memo[s]++;
                cout << s << endl;
                break;
            }
        }
    }
}