#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using ull = unsigned long long;
int main() {
  int N;
  cin >> N;
  string s;
  for (int i = 0; i < N; i++) s += 'a';
  string s1 = s;
  char A = 'a';
  int pos = N - 1;
  bool can[11]{};
  for (int i = 0; i < N; i++) {
    if (i == 0)
      cout << s << endl;
    else {
      s1[pos] = (char)(A + 1);
      pos--;
      cout << s1 << endl;
      s1 = s;
    }
  }
  return 0;
}
