#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    string s(200, 'a');
    cout << s << endl;
    for (int i = 0; i < n; i++) {
      int u;
      cin >> u;
      s[u] = s[u] == 'a' ? 'b' : 'a';
      cout << s << endl;
    }
  }
}
