#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
bool isPrime(long long n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (long long i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
bool isPowerOfTwo(long long x) { return x && (!(x & (x - 1))); }
void bin(unsigned n) {
  unsigned i;
  for (i = 1 << 31; i > 0; i = i / 2) (n & i) ? printf("1") : printf("0");
}
void solve() {
  long long n;
  cin >> n;
  string s(200, 'a');
  cout << s << endl;
  for (long long i = 0; i < n; i++) {
    long long u;
    cin >> u;
    s[u] = (s[u] == 'a') ? 'b' : 'a';
    cout << s << endl;
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t;
  t = 1;
  cin >> t;
  while (t--) {
    solve();
  }
}
