a = int(input())
s = []
for i in range(a):
    b = int(input())
    c = input().split(' ')
    if int(c[0])+int(c[1]) <= int(c[b-1]):
        s.append('1')
        s.append('2')
        s.append('{}'.format(b))
    else:
        s.append('-1')
for j in range(len(s)-2):
    if s[j] == '-1':
        print(-1)
    elif s[j] != '-1' and s[j+1] != '-1' and s[j+2] != '-1':
        print(' '.join(s[j:j+3]))