#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using db = double;
using ld = long double;
template <typename T>
using V = vector<T>;
template <typename T>
using VV = vector<vector<T>>;
constexpr ll mod = 1000000007;
constexpr ll INF = 1000000099;
constexpr ll LINF = (ll)(1e18 + 99);
const vector<ll> dx = {-1, 1, 0, 0}, dy = {0, 0, -1, 1};
template <typename T, typename U>
inline bool chmin(T& t, const U& u) {
  if (t > u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T, typename U>
inline bool chmax(T& t, const U& u) {
  if (t < u) {
    t = u;
    return 1;
  }
  return 0;
}
template <typename T>
inline T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <typename T, typename Y>
inline T mpow(T a, Y n) {
  T res = 1;
  for (; n; n >>= 1) {
    if (n & 1) res = res * a;
    a = a * a;
  }
  return res;
}
signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  int n;
  cin >> n;
  VV<string> v(11, V<string>(0));
  v[0].push_back("a");
  for (ll i = 1; i < (ll)(11); ++i) {
    for (ll j = 0; j < (ll)((ll)(v[i - 1]).size()); ++j) {
      string nex = v[i - 1][j];
      v[i].push_back("a" + nex);
      for (ll k = 0; k < (ll)((ll)(nex).size()); ++k) {
        nex[k]++;
      }
      v[i].push_back("a" + nex);
    }
  }
  sort((v[n - 1]).begin(), (v[n - 1]).end());
  for (ll i = 0; i < (ll)((ll)(v[n - 1]).size()); ++i) {
    cout << v[n - 1][i] << '\n';
  }
}
