#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n, count = 0;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; ++i) {
      cin >> a[i];
    }
    for (int i = 0; i < n - 1; ++i) {
      if (a[i] == a[i + 1] || a[i] + 1 == a[i + 1]) {
        ++count;
      } else {
        count = 0;
      }
    }
    if (count > 0) {
      cout << -1 << endl;
    } else {
      cout << "1 2 3" << endl;
    }
  }
}
