#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    string s(55, 'a');
    int n, k;
    cin >> n;
    cout << s << endl;
    while (n--) {
      cin >> k;
      if (s[k] == 'a') {
        s[k] = 'b';
      } else {
        s[k] = 'a';
      }
      cout << s << endl;
    }
  }
}
