#include <bits/stdc++.h>
using namespace std;
const int MOD = 998244353;
const int INF = 100000002;
const double PI = 4 * atan(1);
const double eps = 1e-7;
const long long oo = 1e18;
int main() {
  long long count = 0;
  int N;
  cin >> N;
  for (int tmp = 0; tmp < (1 << (N - 1)); tmp++) {
    string ans;
    for (int i = 0; i < N; i++) ans.push_back('a');
    bitset<100> s(tmp);
    for (int j = 0; j < N; j++) {
      if (s.test(j)) ans[N - j - 1] = 'b';
    }
    cout << ans << endl;
  }
}
