input:

50000
10 19
12 6 1 12 11 15 4 1 13 18
10 8
8 7 6 7 6 2 2 3 4 8
10 6
3 2 6 6 5 2 3 4 5 6
10 11
6 3 7 9 2 1 2 10 10 4
10 6
6 1 2 6 1 1 3 4 2 1
10 9
8 5 3 9 1 7 5 5 1 1
10 5
1 4 3 2 5 4 5 3 5 2
10 14
3 8 12 10 4 2 3 13 7 3
10 14
5 5 12 2 8 1 13 9 8 5
10 7
5 5 6 6 1 5 3 7 3 4
10 7
5 1 4 6 1 6 4 3 7 5
10...

output:

6
-1
-1
6
3
4
3
-1
5
4
4
5
3
3
-1
-1
-1
5
7
6
-1
-1
-1
2
-1
-1
7
3
-1
-1
6
2
4
3
-1
5
5
3
-1
3
4
6
-1
3
5
5
3
3
3
8
-1
-1
5
-1
4
-1
6
5
-1
-1
-1
6
-1
3
-1
3
-1
7
7
6
-1
-1
4
3
5
5
-1
6
3
4
-1
-1
5
-1
-1
-1
4
5
-1
5
5
-1
2
2
-1
-1
-1
-1
5
3
5
-1
-1
5
-1
7
4
-1
6
6
3
6
4
5
5
-1
6
6
6
7
-1
5
5
-1
4
-1
...

result:

wrong answer 2nd numbers differ - expected: '5', found: '-1'