#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  if (a == 0) {
    return b;
  }
  return gcd(b % a, a);
}
long long int pos(long long int n) {
  if (n >= 0) {
    return n;
  }
  return -n;
}
signed main() {
  long long int t;
  cin >> t;
  while (t--) {
    long long int n;
    cin >> n;
    vector<long long int> v;
    for (long long int i = 0; i < n; i++) {
      long long int z;
      cin >> z;
      v.push_back(z);
    }
    string a = "";
    for (long long int i = 0; i < 100; i++) {
      a += 'a';
    }
    cout << a << "\n";
    for (long long int i = 0; i < n; i++) {
      if (a[v[i]] == 'a') {
        a[v[i]] = 'b';
      } else {
        a[v[i]] = 'a';
      }
      cout << a << "\n";
    }
  }
}
