#include <bits/stdc++.h>
using namespace std;
std::string dec2bin(unsigned n) {
  const int size = sizeof(n) * 8;
  std::string res;
  bool s = 0;
  for (int a = 0; a < size; a++) {
    bool bit = n >> (size - 1);
    if (bit) s = 1;
    if (s) res.push_back(bit + '0');
    n <<= 1;
  }
  if (!res.size()) res.push_back('0');
  return res;
}
int main() {
  int n;
  cin >> n;
  int check = pow(2, n) - 1;
  check = check / 2;
  int curr = 0;
  for (int i = 0; i <= check; i++) {
    string s = dec2bin(curr);
    int k = s.size();
    curr++;
    while (k < n) {
      s = '0' + s;
      k++;
    }
    string ans = "";
    for (int j = 0; j < n; j++) {
      if (s[j] == '0') {
        ans = ans + 'a';
      } else {
        ans = ans + 'b';
      }
    }
    cout << ans << "\n";
  }
  return 0;
}
