#include <bits/stdc++.h>
using namespace std;
inline int read() {
  char ch = getchar();
  int x = 0, f = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') x = x * 10 + (ch ^ 48), ch = getchar();
  return x * f;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    char c = 'a';
    for (int j = 0; j < n; j++) {
      if (j < n - i) {
        cout << "a";
      } else {
        c++;
        cout << c;
      }
    }
    cout << endl;
  }
  return 0;
}
