#include <bits/stdc++.h>
using namespace std;
long long a[10];
int main() {
  ios::sync_with_stdio(false);
  long long n;
  cin >> n;
  long long temp = n - 1, cnt = 0, step = 1;
  while (temp--) {
    cnt *= 10;
    cnt += step;
    step++;
  }
  for (long long i = 0; i < n; i++) {
    cout << "a";
  }
  cout << endl;
  for (long long i = 1; i <= cnt; i++) {
    string s(n - 1, 'a');
    long long f[10];
    long long te = i;
    for (long long j = n - 2; j >= 0; j--) {
      f[j] = te % 10;
      te /= 10;
    }
    for (long long j = 0; j < n - 1; j++) {
      s[j] += f[j];
    }
    cout << "a" + s << endl;
  }
  return 0;
}
