#include <bits/stdc++.h>
using namespace std;
long long int big_mod(long long int b, long long int p, long long int m) {
  long long int ans = 1;
  while (p) {
    if (p % 2 == 1) {
      ans = (b % m * ans % m) % m;
    }
    p = p >> 1;
    b = (b * b) % m;
  }
  return ans;
}
int main() {
  long long int mod, t, k, i, m, n, x, j = 0, c = 0, r = 0, w, s, d = 0, f = 0,
                                       sum = 0, mul, mx1, mx, s1 = 0, s2 = 0;
  cin >> n;
  while (n--) {
    string a = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
    cin >> m;
    f = 0;
    while (m--) {
      cin >> j;
      if (f == 0) {
        cout << a << endl;
        f = 1;
      }
      if (a[j] == 'b') {
        a[j] = 'c';
      } else {
        a[j] = 'b';
      }
      cout << a << endl;
    }
  }
  return 0;
}
