#include <bits/stdc++.h>
using namespace std;
int t;
int n;
int a;
int ans[102];
void output() {
  for (int i = 0; i < 102; i++) {
    cout << (char)(ans[i] + 'a');
  }
  cout << endl;
}
int main() {
  cin >> t;
  while (t--) {
    cin >> n;
    memset(ans, 0, sizeof(ans));
    output();
    for (int i = 0; i < n; i++) {
      cin >> a;
      ans[a]++;
      ans[a] %= 26;
      output();
    }
  }
  return 0;
}
