#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    vector<char> v(200, 'a');
    for (int i = 0; i < 200; i++) cout << v[i];
    cout << endl;
    char c = 'a';
    for (int i = 0; i < n; i++) {
      int x;
      cin >> x;
      for (int j = 0; j < x; j++) cout << v[j];
      if (v[x] == 'a')
        v[x] = 'b';
      else
        v[x] = 'a';
      for (int j = x; j < 200; j++) {
        cout << v[j];
      }
      cout << endl;
    }
  }
  return 0;
}
