#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, n, x, i;
  cin >> t;
  while (t--) {
    cin >> n;
    string s(50, 'a');
    cout << s << endl;
    for (i = 0; i < n; i++) {
      cin >> x;
      if (s[x] == 'a')
        s[x] = 'b';
      else
        s[x] = 'a';
      cout << s << endl;
    }
  }
  return 0;
}
