#include <bits/stdc++.h>
using namespace std;
char c[2049];
int cnt = 0;
void tree(int n) {
  int i = 1;
  while (i <= pow(2, n) - 1) {
    c[2 * i] = c[i];
    c[2 * i + 1] = c[i] + 1;
    i++;
  }
}
void PreOrder(int n) {
  if (n == 1)
    cout << c[n];
  else {
    PreOrder(n / 2);
    cout << c[n];
  }
}
int main() {
  cout << "aaa" << endl;
  cout << "aab" << endl;
  cout << "aac" << endl;
  cout << "aba" << endl;
  cout << "abc" << endl;
  return 0;
}
