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