#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, n;
  string s(100, 'a');
  cin >> t;
  while (t--) {
    cin >> n;
    cout << s << endl;
    for (int i = 0, x; i < n; i++) {
      cin >> x;
      s[x] = ('a' + 'b' - s[x]);
      cout << s << endl;
    }
  }
  return 0;
}
