#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
void solve() {
  int n;
  cin >> n;
  string s(200, 'a');
  cout << s << endl;
  for (int i = 0; i < n; ++i) {
    int u;
    cin >> u;
    s[u] = s[u] == 'a' ? 'b' : 'a';
    cout << s << endl;
  }
}
int main() {
  { ios_base::sync_with_stdio(false); }
  { cin.tie(NULL); }
  cout << setprecision(15) << fixed;
  long long t;
  cin >> t;
  while (t--) {
    solve();
  }
}
