/* -*- coding: utf-8 -*-
 *
 * 701.cc: No.701 ひとりしりとり - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int M = 4;

/* typedef */

/* global variables */

char ds[M];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  for (int i = 0; i < n; i++) {
    putchar('a');
    for (int j = 0; j < M; j++) putchar('a' + ds[j]);
    putchar((i != n - 1) ? 'a' : 'n');
    putchar('\n');

    int k = 0;
    while (k < M) {
      if (++ds[k] < 26) break;
      ds[k++] = 0;
    }
  }
  return 0;
}