1
3
5 3 4
 6
5
5 3 4 4 5
3
1 1 1
5
4 4 3 4 4
5
5 5 4 3 2
3
1 1 2
5
5 4 3 5 5
 1
3
10 1 5

1
 1
-1
2
2
3
1
 1

#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, n;
  cin >> t;
  while (t--) {
    cin >> n;
    int arr[n];
    int ans = -1, mx = -1;
    for (int i = 0; i < n; i++) {
      cin >> arr[i];
    }
    for (int i = 0; i < n; i++) {
      if (i == n - 1 and arr[i] > arr[i - 1] and arr[i] > mx) {
        mx = arr[i];
        ans = i + 1;
        break;
      }
      if (arr[i] > arr[i + 1] and arr[i] > mx) {
        mx = arr[i];
        ans = i + 1;
      } else if (i != 0 and arr[i] > arr[i - 1] and arr[i] > mx) {
        mx = arr[i];
        ans = i + 1;
      }
    }
    cout << ans << endl;
  }
  return 0;
}
