#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
int main() {
  int n;
  cin >> n;
  string s = "";
  for (int i = 0; i < n; i++) s += "a";
  cout << s << endl;
  for (int i = 0; i < n - 1; i++) {
    string t = s;
    t[n - i - 1] = 'b';
    cout << t << endl;
  }
}
