#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll gcd(ll a, ll b) {
  if (a < b) {
    a ^= b;
    b ^= a;
    a ^= b;
  }
  return b ? gcd(b, a % b) : a;
}
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }
int main() {
  ll N;
  cin >> N;
  for (char a = 'a'; a <= 'a'; a++) {
    string S = "aaaaaaaaaa";
    S[0] = a;
    for (char b = 'a'; b <= 'b'; b++) {
      S[1] = b;
      if (N < 3) {
        cout << S.substr(0, N) << endl;
        continue;
      }
      for (char c = 'a'; c <= 'c'; c++) {
        S[2] = c;
        if (N < 4) {
          cout << S.substr(0, N) << endl;
          continue;
        }
        for (char d = 'a'; d <= 'd'; d++) {
          S[3] = d;
          if (N < 5) {
            cout << S.substr(0, N) << endl;
            continue;
          }
          for (char e = 'a'; e <= 'e'; e++) {
            S[4] = e;
            if (N < 6) {
              cout << S.substr(0, N) << endl;
              continue;
            }
            for (char f = 'a'; f <= 'f'; f++) {
              S[5] = f;
              if (N < 7) {
                cout << S.substr(0, N) << endl;
                continue;
              }
              for (char g = 'a'; g <= 'g'; g++) {
                S[6] = g;
                if (N < 8) {
                  cout << S.substr(0, N) << endl;
                  continue;
                }
                for (char h = 'a'; h <= 'h'; h++) {
                  S[7] = h;
                  if (N < 9) {
                    cout << S.substr(0, N) << endl;
                    continue;
                  }
                  for (char i = 'a'; i <= 'i'; i++) {
                    S[8] = i;
                    if (N < 10) {
                      cout << S.substr(0, N) << endl;
                      continue;
                    }
                    for (char j = 'a'; j <= 'j'; j++) {
                      S[9] = j;
                      if (N < 11) {
                        cout << S.substr(0, N) << endl;
                        continue;
                      }
                      cout << S << endl;
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  return 0;
}
