#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n;
  cin >> n;
  string s(200, 'a');
  cout << s << "\n";
  for (long long i = 0; i < n; i++) {
    long long x;
    cin >> x;
    s[x] = s[x] == 'a' ? 'b' : 'a';
    cout << s << "\n";
  }
  return;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long test;
  cin >> test;
  while (test--) solve();
  return 0;
}
