#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  char s[N + 1], temp[N + 1];
  for (int i = 0; i < N; i++) s[i] = 'a';
  cout << s << endl;
  for (int i = 1; i < N; i++) {
    char c = 97 + i;
    for (int j = 1; j < N; j++) {
      char temp = s[j];
      s[N - j] = c;
      cout << s << endl;
      s[N - 1 - j] = temp;
    }
    for (int j = 1; j < N; j++) {
      s[N - j] = c;
      cout << s << endl;
    }
  }
  return 0;
}
