#include <bits/stdc++.h>
int main() {
  unsigned long long N;
  std::cin >> N;
  auto dict = "abcdefghij";
  switch (N) {
    case 1:
      std::cout << "a" << std::endl;
      break;
    case 2:
      std::cout << "aa" << std::endl;
      std::cout << "ab" << std::endl;
      break;
    case 3:
      std::cout << "aaa" << std::endl;
      std::cout << "aab" << std::endl;
      std::cout << "aba" << std::endl;
      std::cout << "abb" << std::endl;
      std::cout << "abc" << std::endl;
      break;
  }
  return 0;
}
