#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f3f3f;
const int N = 2e5 + 10;
int a[N];
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
      cin >> a[i];
    }
    string s = string(200, 'a');
    cout << s << endl;
    for (int i = 1; i <= n; i++) {
      s[a[i]] = s[a[i]] == 'a' ? 'b' : 'a';
      cout << s << endl;
    }
  }
  return 0;
}
