#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using vll = vector<ll>;
string yorn(bool a) {
  if (a) return "Yes";
  return "No";
}
string YorN(bool a) {
  if (a) return "YES";
  return "NO";
}
ll gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
int main() {
  int n;
  cin >> n;
  if (n == 1) {
    cout << 'a' << endl;
    return 0;
  }
  string s;
  for (int i = 0; i < n; i++) s += 'a';
  string t = s;
  for (int i = 0; i < n; i++) {
    cout << s << endl;
    s = t;
    s.at(n - 1 - i) = 'b';
  }
}
