#include <bits/stdc++.h>
using namespace std;
class Solver {
 public:
  void test() {
    { this->solve(); }
  }
  void solve() {
    long long n;
    cin >> n;
    for (long long i = 0; i < n; ++i) {
      for (long long j = 0; j < n - i; ++j) {
        cout << 'a';
      }
      for (long long j = n - i; j < n; ++j) {
        cout << (char)(i + 'a');
      }
      cout << endl;
    }
  }
};
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  Solver S;
  S.test();
  return 0;
}
