#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int t;
  cin >> t;
  while (t--) {
    string s = string(200, 'a');
    long long int n;
    cin >> n;
    cout << s << "\n";
    for (long long int i = 0; i < n; i++) {
      long long int temp;
      cin >> temp;
      if (s[temp] == 'a')
        s[temp] = 'b';
      else
        s[temp] = 'a';
      cout << s << "\n";
    }
  }
  return 0;
}
