import java.util.Scanner;

public class exp37 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t=sc.nextInt();
        while(t>0) {
            int n = sc.nextInt();
            int[] a = new int[n];
            int[] b = new int[n];
            int c = 0, d = 0, e = 0;
            int flag = 0;
            for (int i = 0; i < n; i++) {
                a[i] = sc.nextInt();
                b[i] = a[i];
            }
            int min1=a[0];
            int min2=a[1];
            int max=a[n-1];
            if((min1+min2)<max){
                for(int i=0;i<n;i++){
                    if(min1==b[i] || min2==b[i] || max==b[i]){
                        System.out.print((i+1) + " ");
                    }
                }
            }
            else {
                System.out.println("-1");
            }
            t-=1;
        }
    }
}
