#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  cin >> n;
  int i;
  vector<int> lcp(n);
  for (i = 0; i < n; i++) {
    cin >> lcp[i];
  }
  string s = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
  cout << s << endl;
  for (i = 0; i < n; i++) {
    int idx = lcp[i];
    s[idx] = s[idx] + 1;
    if (s[idx] > 'z') {
      s[idx] = 'a';
    }
    cout << s << endl;
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    solve();
  }
}
