#include <bits/stdc++.h>
int main() {
  int i, j, k, N;
  scanf("%d", &N);
  k = (1 << N) / 2;
  for (i = 0; i < k; ++i) {
    for (j = N - 1; j >= 0; --j) {
      putchar_unlocked('a' + ((i & (1 << j)) != 0));
    }
    putchar_unlocked('\n');
  }
  return 0;
}
