#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
constexpr ll LLINF{1001002003004005006};
int main() {
  int N;
  cin >> N;
  if (N == 1) {
    cout << "a\n";
    return 0;
  } else if (N == 2) {
    cout << "aa\nab\n";
    return 0;
  } else {
    for (int i = 0; i < (N); ++i) {
      for (int j = 0; j < (N - 1); ++j) {
        cout << "a";
      }
      cout << static_cast<char>('a' + i + 1) << '\n';
    }
    return 0;
  }
}
