B"Petya has got an interesting flower. Petya is a busy person, so he sometimes forgets to water it. You are given n days from Petya's live and you have to determine what happened with his flower in the end. The flower grows as follows: At the beginning of the 1 -st day the flower is 1 centimeter tall. What is its height after n days? Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 100 ). Description of the test cases follows. The first line of each test case contains the only integer n ( 1 <= q n <= q 100 ). The second line of each test case contains n integers a_1, a_2, ... , a_n ( a_i = 0 or a_i = 1 ). If a_i = 1 , the flower is watered in the i -th day, otherwise it is not watered. For each test case print a single integer k -- the flower's height after n days, or -1 , if the flower dies. "...