#include <bits/stdc++.h>
using namespace std;
map<int, char> dict;
int main() {
  int N;
  cin >> N;
  dict[1] = 'a';
  dict[2] = 'b';
  dict[3] = 'c';
  dict[4] = 'd';
  dict[5] = 'e';
  dict[6] = 'f';
  dict[7] = 'g';
  dict[8] = 'h';
  dict[9] = 'i';
  dict[10] = 'j';
  for (int i1 = 1; i1 <= 1; i1++) {
    if (N == 1) {
      cout << dict[i1] << endl;
    } else {
      for (int i2 = 1; i2 <= 2; i2++) {
        if (N == 2) {
          cout << dict[i1] << dict[i2] << endl;
        } else {
          for (int i3 = 1; i3 <= 3; i3++) {
            if (N == 3) {
              cout << dict[i1] << dict[i2] << dict[i3] << endl;
            } else {
              for (int i4 = 1; i4 <= 4; i4++) {
                if (N == 4) {
                  cout << dict[i1] << dict[i2] << dict[i3] << dict[i4] << endl;
                } else {
                  for (int i5 = 1; i5 <= 5; i5++) {
                    if (N == 5) {
                      cout << dict[i1] << dict[i2] << dict[i3] << dict[i4]
                           << dict[i5] << endl;
                    } else {
                      for (int i6 = 1; i6 <= 6; i6++) {
                        if (N == 6) {
                          cout << dict[i1] << dict[i2] << dict[i3] << dict[i4]
                               << dict[i5] << dict[i6] << endl;
                        } else {
                          for (int i7 = 1; i7 <= 7; i7++) {
                            if (N == 7) {
                              cout << dict[i1] << dict[i2] << dict[i3]
                                   << dict[i4] << dict[i5] << dict[i6]
                                   << dict[i7] << endl;
                            } else {
                              for (int i8 = 1; i8 <= 8; i8++) {
                                if (N == 8) {
                                  cout << dict[i1] << dict[i2] << dict[i3]
                                       << dict[i4] << dict[i5] << dict[i6]
                                       << dict[i7] << dict[i8] << endl;
                                } else {
                                  for (int i9 = 1; i9 <= 9; i9++) {
                                    if (N == 9) {
                                      cout << dict[i1] << dict[i2] << dict[i3]
                                           << dict[i4] << dict[i5] << dict[i6]
                                           << dict[i7] << dict[i8] << dict[i9]
                                           << endl;
                                    } else {
                                      for (int i10 = 1; i10 <= 10; i10++) {
                                        cout << dict[i1] << dict[i2] << dict[i3]
                                             << dict[i4] << dict[i5] << dict[i6]
                                             << dict[i7] << dict[i8] << dict[i9]
                                             << dict[i10] << endl;
                                      }
                                    }
                                  }
                                }
                              }
                            }
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}
