#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
int main() {
  int n;
  cin >> n;
  for (int a = 0; a < 1; a++) {
    if (n == 1)
      cout << "a" << endl;
    else
      for (int b = 0; b < 2; b++) {
        if (n == 2)
          cout << "a" << char('a' + b) << endl;
        else
          for (int c = 0; c < 3; c++) {
            if (n == 3)
              cout << "a" << char('a' + b) << char('a' + c) << endl;
            else
              for (int d = 0; d < 4; d++) {
                if (n == 4)
                  cout << "a" << char('a' + b) << char('a' + c) << char('a' + d)
                       << endl;
                else
                  for (int e = 0; e < 5; e++) {
                    if (n == 5)
                      cout << "a" << char('a' + b) << char('a' + c)
                           << char('a' + d) << char('a' + e) << endl;
                    else
                      for (int f = 0; f < 6; f++) {
                        if (n == 6)
                          cout << "a" << char('a' + b) << char('a' + c)
                               << char('a' + d) << char('a' + e)
                               << char('a' + f) << endl;
                        for (int g = 0; g < 7; g++) {
                          if (n == 7)
                            cout << "a" << char('a' + b) << char('a' + c)
                                 << char('a' + d) << char('a' + e)
                                 << char('a' + f) << char('a' + g) << endl;
                          else
                            for (int h = 0; h < 8; h++) {
                              if (n == 8)
                                cout << "a" << char('a' + b) << char('a' + c)
                                     << char('a' + d) << char('a' + e)
                                     << char('a' + f) << char('a' + g)
                                     << char('a' + h) << endl;
                              else
                                for (int i = 0; i < 9; i++) {
                                  if (n == 9)
                                    cout << "a" << char('a' + b)
                                         << char('a' + c) << char('a' + d)
                                         << char('a' + e) << char('a' + f)
                                         << char('a' + g) << char('a' + h)
                                         << char('a' + i) << endl;
                                  else
                                    for (int j = 0; j < 10; j++) {
                                      if (n == 10)
                                        cout << "a" << char('a' + b)
                                             << char('a' + c) << char('a' + d)
                                             << char('a' + e) << char('a' + f)
                                             << char('a' + g) << char('a' + h)
                                             << char('a' + i) << char('a' + j)
                                             << endl;
                                    }
                                }
                            }
                        }
                      }
                  }
              }
          }
      }
  }
}
