Comments
On Lewin → Codeforces Round #385 Editorial, 10 years ago
+3

I used almost the same approach, and came up with asking questions like:

1, 3, 5, 7, 9...
2, 4, 6, 8, 10...
1, 2, 5, 6, 9...
3, 4, 7, 8, 11...
1, 2, 3, 4, 9...
5, 6, 7, 8, 13...

But its failing on test 7 don't know why :(