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

import java.util.*;
public class Solution
{
       public static void main(String []args)
       {
              Scanner sc = new Scanner(System.in);
             int t = sc.nextInt();
             while(t-- > 0)
             {
                    int n = sc.nextInt();
                    int arr[] = new int[n];
                    int max = 0;
                    for(int i = 0 ; i < n ; i++)
                    {
                           arr[i] = sc.nextInt();
                           max = Math.max(max,arr[i]);
                    }
                    int pos = -1;
                    for(int i = 0 ; i < n ; i++)
                    {
                           if(arr[i] == max)
                           {
                                  if((i-1 >= 0 && arr[i-1] < max) || (i+1 < n && arr[i+1] < max))
                                  {
                                         pos = i+1;
                                         break;
                                  }
                           }
                    }
                    System.out.println(pos);
             }
       }
}
