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

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

ll ll_pow(ll a, ll n){
    ll v = 1;
    FOR(i, 0, n){
        v *= a;
    }
    return v;
}

// 長さ4
string encode26(ll v){
    vector<ll> A(4);
    FOR(i, 0, 4){
        A[i] = v % ll_pow(26, i+1);
        v /= 26;
    }
    string s = "aaaa";
    FOR(i, 0, 4){
        s[i] = 'a' + A[i];
    }
    reverse(ALL(s));
    return s;
}

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

    // input
    ll N;
    cin >> N;

    FOR(i, 0, N-1){
        stringstream ss;
        ss << 'a';
        ss << encode26(i);
        ss << 'a';
        p(ss.str());
    }

    p("an");

    
    return 0;
}