#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    string s(100, 'a');
    cout << s << endl;
    for (int i = 0; i < n; i++) {
      int x;
      cin >> x;
      if (s[x] == 'a')
        s[x] = 'b';
      else
        s[x] = 'a';
      cout << s << endl;
    }
  }
  return 0;
}
