#include <bits/stdc++.h>
using namespace std;
char s[151];
int main() {
  int t;
  scanf("%d", &t);
  while (t--) {
    int n, a[105];
    scanf("%d", &n);
    int maxn = -1;
    for (int i = 0; i < n; i++) scanf("%d", &a[i]), maxn = max(maxn, a[i]);
    maxn++;
    for (int i = 0; i < maxn; i++) {
      s[i] = 'a';
    }
    cout << s << endl;
    for (int i = 0; i < n; i++) {
      if (s[a[i]] == 'z')
        s[a[i]] = 'a';
      else
        s[a[i]] = ++s[a[i]];
      cout << s << endl;
    }
  }
  return 0;
}
