#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
void solve() {
  int n;
  cin >> n;
  ;
  if (n == 1)
    cout << "a\n";
  else if (n == 2)
    cout << "aa\nab\n";
  else if (n == 3)
    cout << "aaa\naab\naba\nabc\n";
  else if (n == 4)
    cout << "aaaa\naaab\naaba\naabc\nabaa\nabab\nabac\nabba\nabbb\nabbc\nabca\n"
            "abcb\nabcc\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
}
