#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using namespace std;
int main() {
  int N;
  cin >> N;
  if (N == 1) {
    cout << "a" << endl;
    return 0;
  }
  if (N == 2) {
    cout << "aa" << endl;
    cout << "ab" << endl;
    return 0;
  }
  string ans(N, 'a'), tmp = ans;
  int cur = N;
  for (int(i) = (0); (i) < (int)(N); ++(i)) {
    if (cur < N) {
      tmp[cur] = 'b';
    }
    cout << tmp << endl;
    tmp = ans;
    cur--;
  }
}
