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