#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n;
  cin >> n;
  string tmp, s = "";
  for (long long i = 0; i < n; i++) s += 'a';
  long long m = pow(2, n - 1);
  for (long long i = 0; i < m; i++) {
    tmp = s;
    for (long long j = 32; j >= 0; j--) {
      if ((i >> j) & 1) tmp[n - j - 1] = 'b';
    }
    cout << tmp << '\n';
  }
}
