#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
int main() {
  int n;
  cin >> n;
  string s;
  for (int i = 0; i < n; i++) {
    s += 'a';
  }
  for (int i = 0; i < min(26, n); i++) {
    if (i == 0) {
      cout << s << endl;
      continue;
    }
    for (int j = n - 1; i <= j; j--) {
      s[j]++;
    }
    cout << s << endl;
  }
  return 0;
}
