#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
void solve() {
  int n;
  cin >> n;
  string s(200, 'a');
  cout << s << "\n";
  for (int i = 0; i < n; ++i) {
    int x;
    cin >> x;
    if (s[x] == 'a')
      s[x] = 'b';
    else
      s[x] = 'a';
    cout << s << "\n";
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int t = 1;
  cin >> t;
  while (t--) {
    solve();
  }
}
