#include <iostream>
#include <algorithm>
using namespace std;
int main(){
  int n;cin>>n;
  string x = "abcdefghijklmnopqr";
  for(int i = 0; n-1 > i; i++){
    cout << "a" << x << "a" << endl;
    next_permutation(x.begin(),x.end());
  }
  next_permutation(x.begin(),x.end());
  cout << "a" << x << "n" << endl; 
}