#include <bits/stdc++.h>
using namespace std;
int n;
void print(vector<string> ans) {
  for (auto x : ans) cout << x << endl;
}
int main() {
  cin >> n;
  if (n == 1) {
    vector<string> ans = {"a"};
    print(ans);
  }
  if (n == 2) {
    vector<string> ans = {"aa", "ab"};
    print(ans);
  }
  if (n == 3) {
    vector<string> ans = {"aaa", "aab", "aba"};
    print(ans);
  }
  if (n == 4) {
    vector<string> ans = {"aaaa", "aaab", "aaba", "aabb"};
    print(ans);
  }
  if (n == 5) {
    vector<string> ans = {"aaaaa", "aaaab", "aaaba", "aaabb", "aaabc"};
    print(ans);
  }
  if (n == 6) {
    vector<string> ans = {"aaaaaa", "aaaaab", "aaaaba",
                          "aaaabb", "aaaabc", "aaabaa"};
    print(ans);
  }
  if (n == 7) {
    vector<string> ans = {"aaaaaaa", "aaaaaab", "aaaaaba", "aaaaabb",
                          "aaaaabc", "aaaabaa", "aaaabab"};
    print(ans);
  }
  if (n == 8) {
    vector<string> ans = {"aaaaaaaa", "aaaaaaab", "aaaaaaba", "aaaaaabb",
                          "aaaaaabc", "aaaaabaa", "aaaaabab", "aaaaabac"};
    print(ans);
  }
  if (n == 9) {
    vector<string> ans = {"aaaaaaaaa", "aaaaaaaab", "aaaaaaaba",
                          "aaaaaaabb", "aaaaaaabc", "aaaaaabaa",
                          "aaaaaabab", "aaaaaabac", "aaaaaabba"};
    print(ans);
  }
  if (n == 10) {
    vector<string> ans = {
        "aaaaaaaaaa", "aaaaaaaaab", "aaaaaaaaba", "aaaaaaaabb", "aaaaaaaabc",
        "aaaaaaabaa", "aaaaaaabab", "aaaaaaabac", "aaaaaaabba", "aaaaaaabbb"};
    print(ans);
  }
  return 0;
}
