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 k;
  cin >> k;
  while (k--) {
    int n, temp = 0, count = 0;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    for (int i = 1; i < n; i++) {
      if (a[0] == a[i]) {
        count++;
      } else {
        if (a[0] < a[i]) {
          temp = i;
        }
      }
    }
    if (count == n - 1) {
      cout << -1 << endl;
    } else {
      cout << temp + 1 << endl;
    }
  }
}
