#include <bits/stdc++.h>
using namespace std;
int n, t;
int A[2001];
void init() {
  cin >> n;
  for (int i = 0; i < n; i++) cin >> A[i];
}
void obl() {
  string s = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
  cout << s << "\n";
  for (int i = 0; i < n; i++) {
    for (int j = A[i]; j < 50; j++)
      if (s[j] == 'a')
        s[j] = 'b';
      else
        s[j] = 'a';
    cout << s << "\n";
  }
}
int main() {
  cin >> t;
  while (t-- > 0) {
    init();
    obl();
  }
}
