#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) printf("a");
  printf("\n");
  for (int i = 1; i < n - 1; i++) {
    for (int k = n - i; k >= 0; k--) {
      for (int j = 1; j <= k; j++) printf("a");
      for (int j = 1; j <= i; j++) printf("%c", j + 'a');
      for (int j = 1; j <= (n - k - i); j++) printf("a");
      printf("\n");
    }
  }
  for (int i = 0; i < n; i++) printf("%c", i + 'a');
  printf("\n");
}
