//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int siz(string s){
  return (int)s.size();
}

int main(){
  int N; cin >> N;
  string ans = "aaaaaaaaaaaaaaaaaaaa";
  map<string, int> mp;

  for(int i = 1; i <= N; i++){
    if(i == N){
      ans[0] = ans[19];
      ans[19] = 'n';

      bool flag = false;
      for(int j = 1; j <= 18; j++){
        for(int k = 0; k < 26; k++){
          ans[j] = 'a'+k;

          if(mp[ans] == 0){
            mp[ans]++;
            flag = true;
          }

          if(flag) break;
        }

        if(flag) break;
      }

      printl(ans);
    }else{
      ans[0] = ans[19];

      bool flag = false;
      for(int j = 1; j <= 19; j++){
        for(int k = 0; k < 26; k++){
          ans[j] = 'a'+k;

          if(mp[ans] == 0){
            mp[ans]++;
            flag = true;
          }

          if(flag) break;
        }

        if(flag) break;
      }

      printl(ans);
    }
  }

  return 0;
}