#include <bits/stdc++.h>
#pragma GCC optimize(3, "Ofast", "inline")
using namespace std;
template <class T>
void _sf(T &x) {
  cin >> x;
}
void _sf(int &x) { scanf("%d", &x); }
void _sf(long long &x) { scanf("%lld", &x); }
void _sf(double &x) { scanf("%lf", &x); }
void _sf(char &x) { scanf(" %c", &x); }
void _sf(char *x) { scanf("%s", x); }
void sf() {}
template <class T, class... U>
void sf(T &head, U &...tail) {
  _sf(head);
  sf(tail...);
}
template <class T>
void _out(const T &x) {
  cout << x;
}
void _out(const int &x) { printf("%d", x); }
void _out(const long long &x) { printf("%lld", x); }
void _out(const double &x) { printf("%.16f", x); }
void _out(const char &x) { putchar(x); }
void _out(const char *x) { printf("%s", x); }
template <class T, class U>
void _out(const pair<T, U> &x) {
  _out(x.F);
  putchar(' ');
  _out(x.S);
}
template <class T>
void _out(const vector<T> &x) {
  for (auto i = x.begin(); i != x.end(); _out(*i++))
    if (i != x.cbegin()) putchar(' ');
}
void out() {}
template <class T, class... U>
void out(const T &head, const U &...tail) {
  _out(head);
  putchar(sizeof...(tail) ? ' ' : '\n');
  out(tail...);
}
const int mod = 1e9 + 7;
const int INF = 0x3f3f3f3f;
int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
int aa[11];
int n;
map<char, char> m;
string f(string s) {
  m.clear();
  string ret;
  for (int i = 0; i < s.size(); i++) {
    if (m.find(s[i]) == m.end()) {
      if (m.empty()) {
        m[s[i]] = 'a';
      } else {
        m[s[i]] = m[s[i - 1]] + 1;
      }
    }
    ret += m[s[i]];
  }
  return ret;
}
map<string, bool> mm;
void solve(int x, string &s) {
  if (x == n) {
    string temp = f(s);
    if (mm.count(temp) == 0) {
      out(s);
      mm[temp] = 1;
    }
    return;
  }
  for (char i = 'a'; i <= 'a' + x; ++i) {
    s.push_back(i);
    solve(x + 1, s);
    s.pop_back();
  }
  return;
}
int main() {
  n = read();
  for (int i = 1; i <= n; ++i) aa[i] = i;
  string s;
  solve(0, s);
  return 0;
}
