#include <bits/stdc++.h>
char str[20];
int n;
void check(int p, char ch) {
  if (p == n) {
    str[p] = ch;
    for (int i = 1; i <= n; ++i) printf("%c", str[i]);
    printf("\n");
    str[p] = ch + 1;
    for (int i = 1; i <= n; ++i) printf("%c", str[i]);
    printf("\n");
    return;
  }
  str[p] = ch;
  check(p + 1, ch);
  str[p] = ch + 1;
  check(p + 1, ch + 1);
}
int main() {
  scanf("%d", &n);
  str[1] = 'a';
  if (n >= 2)
    check(2, 'a');
  else
    printf("a");
  return 0;
}
