#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, a;
  cin >> t;
  string s("");
  for (int p = 0; p < 200; p++) {
    s = s + 'a';
  }
  for (int i = 0; i < t; i++) {
    int n;
    cin >> n;
    cout << s << "\n";
    for (int k = 0; k < n; k++) {
      cin >> a;
      if (s[a] == 'a') {
        s[a] = 'b';
      } else
        s[a] = 'a';
      cout << s << "\n";
    }
  }
}
