#include <bits/stdc++.h>
using namespace std;
const int inf = 1000000000;
bool cmp(pair<int, int> a, pair<int, int> b) { return a.second < b.second; }
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    string s(199, 'a');
    string op = s;
    int a[n];
    cout << s << "\n";
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      string s1 = "";
      s1 += op.substr(0, a[i]);
      for (int k = a[i]; k < 199; k++) {
        int j = op[k] - 'a';
        j = (j + 1) % 26;
        s1 += (char)('a' + j);
      }
      cout << s1 << endl;
      op = s1;
    }
  }
}
