#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, k;
  cin >> n;
  int C[n], D;
  for (k = 0; k < n * n / 2; k++) {
    D = k;
    for (i = n - 1; i >= 0; i--) {
      C[i] = D % n;
      D = D / n;
    }
    for (i = 0; i < n; i++) {
      cout << (char)(97 + C[i]);
    }
    cout << endl;
  }
}
