#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, len, now;
  cin >> n;
  for (int i = 0; i < n; i++) cout << 'a';
  cout << endl;
  string s;
  for (int i = 1; i < n - 1; i++) {
    s += 'a' + i;
    now = n - i;
    while (now != -1) {
      for (int j = 0; j < now; j++) cout << 'a';
      cout << s;
      for (int j = now + i; j < n; j++) cout << 'a';
      cout << endl;
      now--;
    }
  }
  for (int i = 0; i < n; i++) cout << char(i + 'a');
  return 0;
}
