#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5e5 + 5;
const int MOD = 998244353;
string ans[50];
int main() {
  int n;
  while (cin >> n) {
    ans[1] = "";
    for (int i = 1; i <= n; i++) ans[1] += 'a';
    for (int i = 2; i <= n; i++) {
      ans[i] = ans[i - 1];
      for (int j = i - 1; j <= n - 1; j++) {
        ans[i][j] = 'a' + i - 1;
      }
    }
    for (int i = 1; i <= n; i++) {
      cout << ans[i] << endl;
    }
  }
}
