#include <bits/stdc++.h>
using namespace std;
int a[2000];
string s;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    s = string(60, 'a');
    cout << s << "\n";
    for (int i = 1; i <= n; ++i) {
      s[a[i]] = s[a[i]] + 1;
      if (s[a[i]] > 'z') s[a[i]] = 'a';
      cout << s << "\n";
    }
  }
  return 0;
}
