import java.io.*;

public class A {
	public static void main(String[] args) throws NumberFormatException, IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		int cases = Integer.valueOf(br.readLine());
		while (cases-- > 0) {
			int len = Integer.valueOf(br.readLine());
			String[] line = br.readLine().split(" ");
			int[] data = new int[len];
			
			int a = Integer.valueOf(line[0]);
			int b = Integer.valueOf(line[1]);
			for (int i = 0 ; i < len ; i++) {
				data[i] = Integer.valueOf(line[i]);
				data[i] -= a;
			}
			
			boolean isImpossible = false;
			StringBuilder sb = new StringBuilder();
			int i;
			for (i = 2 ; i < len ; i++) {
				if (b < data[i]) {
					isImpossible = true;
					break;
				}
			}
			sb.append("1 2 ").append(i + 1);
				
			if (isImpossible) System.out.println(sb.toString());
			else 			  System.out.println(-1);
		}
	}
}
