#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
const long long INF = 8e18;
const int maxn = 5e5 + 5;
char a[110][110];
int x[110];
int main() {
  int t;
  scanf("%d", &t);
  a[0][0] = 'a';
  for (int i = 1; i <= 105; ++i) {
    if (a[0][i - 1] == 122)
      a[0][i] = 97;
    else
      a[0][i] = a[0][i - 1] + 1;
  }
  while (t--) {
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i) {
      scanf("%d", &x[i]);
    }
    for (int i = 1; i <= n; ++i) {
      for (int j = 0; j < 102; ++j) a[i][j] = a[i - 1][j];
      if (a[i - 1][x[i]] == 122)
        a[i][x[i]] = 97;
      else
        a[i][x[i]] = a[i - 1][x[i]] + 1;
    }
    for (int i = 0; i < n + 1; ++i) {
      for (int j = 0; j < 102; ++j) printf("%c", a[i][j]);
      printf("\n");
    }
  }
}
