#include<bits/stdc++.h>
#define f first
#define s second
#define pb push_back
using namespace std;

string a="aaaaaaaaaa";
int n;
vector<bool> dir(5);
vector<string> vals;
void rec(int pos){
    if(pos==5)return;
    while(vals.size()<=n){
        rec(pos+1);
        if(a[pos*2]=='a'&&dir[pos]){
            dir[pos]=0;
            break;
        }
        if(a[pos*2]=='z'&&!dir[pos]){
            dir[pos]=1;
            break;
        }
        if(!dir[pos]){
            a[2*pos]++;
            vals.pb(a);
            a[2*pos+1]++;
            vals.pb(a);
        }
        else{
            a[2*pos]--;
            vals.pb(a);
            a[2*pos+1]--;
            vals.pb(a);
        }
    }
}

int main(){
    scanf("%i",&n);
    vals.pb(a);
    rec(0);
    for(int i=0;i<n;i++){
        cout << vals[i] << endl;
    }
}