#include <bits/stdc++.h>
using namespace std;
using int64 = long long;
int64 max(int64 a, int64 b) {
  if (b > a)
    return b;
  else
    return a;
}
int64 min(int64 a, int64 b) {
  if (b < a)
    return b;
  else
    return a;
}
signed main() {
  int64 N;
  cin >> N;
  string S = "";
  for (int64 i = 0; i < N; i++) S += 'a';
  if (N == 1)
    cout << 'a' << endl;
  else {
    for (int64 a = 0; a < 2; a++) {
      string ta = S;
      ta[1] += a;
      if (N == 2) {
        cout << ta << endl;
        continue;
      }
      for (int64 b = 0; b < a + 2; b++) {
        string tb = ta;
        tb[2] += b;
        if (N == 3) {
          cout << tb << endl;
          continue;
        }
        for (int64 c = 0; c < b + 2; c++) {
          string tc = tb;
          tc[3] += c;
          if (N == 4) {
            cout << tc << endl;
            continue;
          }
          for (int64 d = 0; d < c + 2; d++) {
            string td = tc;
            td[4] += d;
            if (N == 5) {
              cout << td << endl;
              continue;
            }
            for (int64 e = 0; e < d + 2; e++) {
              string te = td;
              te[5] += e;
              if (N == 6) {
                cout << te << endl;
                continue;
              }
              for (int64 f = 0; f < e + 2; f++) {
                string tf = te;
                tf[6] += f;
                if (N == 7) {
                  cout << tf << endl;
                  continue;
                }
                for (int64 g = 0; g < f + 2; g++) {
                  string tg = tf;
                  tg[7] += g;
                  if (N == 8) {
                    cout << tg << endl;
                    continue;
                  }
                  for (int64 h = 0; h < g + 2; h++) {
                    string th = tg;
                    th[8] += h;
                    if (N == 9) {
                      cout << th << endl;
                      continue;
                    }
                    for (int64 i = 0; i < h + 2; i++) {
                      string t = th;
                      t[9] += i;
                      cout << t << endl;
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  return 0;
}
