#include <bits/stdc++.h>
using namespace std;
void solve() {
  int i, j, k, m, n, ans = 0, cnt = 0;
  cin >> n;
  string s(200, 'a');
  cout << s << endl;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    s[x] = s[x] == 'a' ? 'b' : 'a';
    cout << s << endl;
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t;
  cin >> t;
  while (t--) solve();
  return 0;
}
