#include <bits/stdc++.h>
const int maxn = 1e5 + 10;
const int mod = 1e9 + 7;
const double eps = 1e-15;
using namespace std;
map<long long, int> mp;
int n;
int a[11];
int ans[11] = {0};
void check() {
  for (int i = n - 1; i >= 1; i--) {
    if (ans[i] / a[i]) {
      ans[i - 1] += 1;
      ans[i] %= a[i];
    }
  }
}
void fi() {
  for (int i = 0; i < n; i++) {
    printf("%c", ans[i] + 'a');
  }
  printf("\n");
}
void fuck() {
  long long tmp = 0;
  int vis[11] = {0};
  int cnt = 1;
  for (int i = 0; i < n; i++) {
    if (vis[ans[i]] == 0) {
      vis[ans[i]] = cnt++;
    }
  }
  for (int i = 0; i < n; i++) {
    tmp = 10 * tmp + vis[ans[i]];
  }
  if (mp[tmp] == 0) {
    fi();
    mp[tmp] = 1;
  }
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) a[i] = i + 1;
  while (ans[0] != 1) {
    fuck();
    ans[n - 1] += 1;
    check();
  }
}
