#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> P;
long long MOD = 1000000007;
int main() {
  int n;
  cin >> n;
  if (n > 9) {
    n = 9;
  }
  string s[n];
  char x = 'a';
  char y;
  for (int i1 = 0; i1 < 1; i1++) {
    x = 'a';
    y = x + i1;
    s[0] = y;
    if (n == 1) {
      for (int i = 0; i < n; i++) {
        cout << s[i];
      }
      cout << endl;
      continue;
    }
    for (int i2 = 0; i2 < i1 + 2; i2++) {
      x = 'a';
      y = x + i2;
      s[1] = y;
      if (n == 2) {
        for (int i = 0; i < n; i++) {
          cout << s[i];
        }
        cout << endl;
        continue;
      }
      for (int i3 = 0; i3 < i2 + 2; i3++) {
        x = 'a';
        y = x + i3;
        s[2] = y;
        if (n == 3) {
          for (int i = 0; i < n; i++) {
            cout << s[i];
          }
          cout << endl;
          continue;
        }
        for (int i4 = 0; i4 < i3 + 2; i4++) {
          x = 'a';
          y = x + i4;
          s[3] = y;
          if (n == 4) {
            for (int i = 0; i < n; i++) {
              cout << s[i];
            }
            cout << endl;
            continue;
          }
          for (int i5 = 0; i5 < i4 + 2; i5++) {
            x = 'a';
            y = x + i5;
            s[4] = y;
            if (n == 5) {
              for (int i = 0; i < n; i++) {
                cout << s[i];
              }
              cout << endl;
              continue;
            }
            for (int i6 = 0; i6 < i5 + 2; i6++) {
              x = 'a';
              y = x + i6;
              s[5] = y;
              if (n == 6) {
                for (int i = 0; i < n; i++) {
                  cout << s[i];
                }
                cout << endl;
                continue;
              }
              for (int i7 = 0; i7 < i6 + 2; i7++) {
                x = 'a';
                y = x + i7;
                s[6] = y;
                if (n == 7) {
                  for (int i = 0; i < n; i++) {
                    cout << s[i];
                  }
                  cout << endl;
                  continue;
                }
                for (int i8 = 0; i8 < i7 + 2; i8++) {
                  x = 'a';
                  y = x + i8;
                  s[7] = y;
                  if (n == 8) {
                    for (int i = 0; i < n; i++) {
                      cout << s[i];
                    }
                    cout << endl;
                    continue;
                  }
                  for (int i9 = 0; i9 < i8 + 2; i9++) {
                    x = 'a';
                    y = x + i9;
                    s[8] = y;
                    if (n == 9) {
                      for (int i = 0; i < n; i++) {
                        cout << s[i];
                      }
                      cout << endl;
                      continue;
                    }
                    for (int i10 = 0; i10 < i9 + 2; i10++) {
                      x = 'a';
                      y = x + i10;
                      s[9] = y;
                      if (n == 10) {
                        for (int i = 0; i < n; i++) {
                          cout << s[i];
                        }
                        cout << endl;
                        continue;
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  return 0;
}
