B'This is an interactive problem. If you are unsure how interactive problems work, then it is recommended to read the guide for participants. Before the last stage of the exam, the director conducted an interview. He gave Gon n piles of stones, the i -th pile having a_i stones. Each stone is identical and weighs 1 grams, except for one special stone that is part of an unknown pile and weighs 2 grams. Gon can only ask the director questions of one kind: he can choose k piles, and the director will tell him the total weight of the piles chosen. More formally, Gon can choose an integer k ( 1 <= q k <= q n ) and k unique piles p_1, p_2, ... , p_k ( 1 <= q p_i <= q n ), and the director will return the total weight m_{p_1} + m_{p_2} + ... + m_{p_k} , where m_i denotes the weight of pile i . Gon is tasked with finding the pile that contains the special stone. However, the director is busy. Help Gon find this pile in at most mathbf{30} queries. The input data contains several test cases. The first line contains one integer t ( 1 <= q t <= q 1000 ) -- the number of test cases. The description of the test cases follows. The first line of each test case contains a single integer n ( 1 <= q n <= q 2 cdot 10^5 ) -- the number of piles. The second line of each test case contains n integers a_i ( 1 <= q a_i <= q 10^4 ) -- the number of stones in each pile. It is guaranteed that the sum of n over all test cases does not exceed 2 cdot 10^5 . After reading the input for each test case, proceed with the interaction as follows. You can perform the operation at most mathbf{30} times to guess the pile. To make a guess, print a line with the following format: When you know the index of the pile with the special stone, print one line in the following format: texttt{!} m ( 1 <= q m <= q n ). After that, move on to the ne'...