#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  if (n == 1) {
    cout << "a" << endl;
    return 0;
  }
  for (int i = 0; i < 1 << (n - 1); i++) {
    int a = n;
    int x = i;
    cout << "a";
    while (a >= 2) {
      if (x - pow(2, a - 2) >= 0) {
        cout << "b";
        x -= pow(2, a - 2);
      } else
        cout << "a";
      a--;
    }
    cout << endl;
  }
}
