#include <bits/stdc++.h>
using namespace std;
const int N = 4e5 + 5;
string ans[N];
void solve() {
  int n;
  cin >> n;
  string lst = "";
  for (int i = 0; i < 52; i++) lst += 'a';
  ans[0] = lst;
  for (int i = 1; i <= n; i++) {
    int x;
    cin >> x;
    string now = "";
    for (int j = 0; j < 52; j++) {
      if (j == x) {
        if (lst[j] == 'a')
          now += 'b';
        else
          now += 'a';
      } else
        now += lst[j];
    }
    ans[i] = now;
    lst = now;
  }
  for (int i = 0; i <= n; i++) cout << ans[i] << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  cin >> t;
  while (t--) solve();
  return 0;
}
