#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  for (int bit = 0; bit < (1 << n); bit++) {
    if (bit % 2 == 1) continue;
    for (int i = 0; i < (n); i++) {
      if (bit & (1 << i))
        cout << 'b';
      else
        cout << 'a';
    }
    if (s[0] != 'b') cout << s;
    s = "";
    cout << endl;
  }
}
