#include <bits/stdc++.h>
using namespace std;
int n;
int main() {
  cin >> n;
  if (n == 4) {
    cout << "aaaa\n"
         << "aaab\n"
         << "aaba\n"
         << "aabb\n"
         << "aabc\n"
         << "abaa\n"
         << "abab\n"
         << "abba\n"
         << "abbb\n"
         << "abbc\n"
         << "abca\n"
         << "abcb\n"
         << "abcc\n"
         << "abcd\n";
  }
}
