Icecream_parlor

// https://www.hackerrank.com/challenges/icecream-parlor/problem

#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the icecreamParlor function below.
def icecreamParlor(m, arr):
    result = []
    for idx,val in enumerate(arr):
        if(m-val in arr[idx+1:]):
            result.append(idx+1)
            #print(arr[idx+1:].index(m-val) + idx + 2)
            result.append(arr[idx+1:].index(m-val)+idx+2)
            break
    if(len(result)>0):
        return result
    else:
        return -1

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    t = int(input())

    for t_itr in range(t):
        m = int(input())

        n = int(input())

        arr = list(map(int, input().rstrip().split()))

        result = icecreamParlor(m, arr)

        fptr.write(' '.join(map(str, result)))
        fptr.write('\n')

    fptr.close()