#include <bits/stdc++.h>
using namespace std;
int main() {
  int q;
  cin >> q;
  while (q--) {
    int n;
    cin >> n;
    int a[n], i, j, k, l, m;
    string s, temp;
    for (i = 0; i < n; i++) cin >> a[i];
    char c = 'a', d;
    for (i = 0; i <= 50; i++) {
      s += 'a';
    }
    cout << s << endl;
    for (i = 0; i < n; i++) {
      k = a[i];
      temp = "\0";
      for (j = 0; j < k; j++) {
        temp += s[j];
        c = s[j];
      }
      for (j = k; j <= 50; j++) {
        if (s[j] != 'z') {
          d = s[j] + 1;
        } else {
          d = 'a';
        }
        temp += d;
      }
      s = temp;
      cout << temp << endl;
    }
  }
  return 0;
}
