#include <bits/stdc++.h>
using namespace std;
const long long N = (long long)50;
long long n, t;
string s;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> t;
  while (t--) {
    s = "";
    cin >> n;
    for (long long i = 1; i <= 50; i++) s += 'a';
    cout << s << "\n";
    long long x;
    while (n--) {
      string s1 = "";
      cin >> x;
      for (long long i = 0; i <= x - 1; i++) {
        s1 += s[i];
      }
      char y;
      for (long long i = x; i <= s.size() - 1; i++) {
        if (s[i] - 1 < 'a')
          y = (char)(s[i] + 1);
        else
          y = (char)(s[i] - 1);
        s1 += y;
      }
      cout << s1 << "\n";
      s = s1;
    }
  }
}
