#include<bits/stdc++.h>
using namespace std;
using ll=long long;
vector<string> init(){
    vector<string>A;
    string x="aa";
    while(1){
        A.push_back(x);
        if(x=="zz")break;
        if(x[0]==x[1])x[1]++;
        else x[0]++;
    }
    for(ll t=0;t<2;t++){
        vector<string>B;
        ll k=A.size();
        for(ll i=0;i<k;i++){
            if(i%4==0){
                for(ll j=0;j<k;j++)B.push_back(A[i]+A[j]);
            }else if(i%4==1){
                B.push_back(A[i]+A[k-1]);
            }else if(i%4==2){
                for(ll j=k-1;j>=0;j--)B.push_back(A[i]+A[j]);
            }else{
                B.push_back(A[i]+A[0]);
            }
        }
        A=B;
    }
    return A;
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    vector<string>A=init();
    ll n;
    cin>>n;
    for(ll i=0;i<n;i++){
        cout<<A[i]<<"\n";
    }
}