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

int main() {
    int n;
    cin>>n;
    for (int i=0;i<n-1;i++) {
        string s="a";
        int t=i;
        while (t) {
            s+=t%26+'a';
            t/=26;
        }
        s+="a";
        cout<<s<<endl;
    }
    cout<<"an"<<endl;
    return 0;
}