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;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int arr[n];
    for (int i = 0; i < n; i++) cin >> arr[i];
    int max = 0;
    for (int i = 0; i < n; i++) {
      if (arr[i] > max) max = arr[i];
    }
    int index = -1;
    for (int i = 0; i < n; i++) {
      if (arr[i] == max) {
        if ((i > 0 && arr[i] > arr[i - 1]) ||
            (i < n - 1 && arr[i] > arr[i + 1])) {
          index = i + 1;
          break;
        }
      }
    }
    cout << index << endl;
  }
}
