B'You have a sequence a_1, a_2, ldots, a_n of length n , each element of which is either 0 or 1 , and a sequence b , which is initially empty. You are going to perform n operations. On each of them you will increase the length of b by 1 . You can find examples of operations in the Notes section. Determine if there exists a sequence of operations that makes b equal to a . If such sequence of operations exists, find it. Each test contains multiple test cases. The first line contains a single integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The first line of each test case contains one integer n ( 1 <= n <= 10^5 ) -- the length of the sequence a . The second line of each test case contains n integers a_1, a_2, ldots, a_n ( 0 <= a_i <= 1 ) -- the sequence a . It is guaranteed that the sum of n over all test cases does not exceed 10^5 . For each test case: In the first test case, Hence, sequence b changes in the following way: [ ,] xrightarrow{p , = , 0} [ , underline{0} ,] xrightarrow{p , = , 0} [ , underline{0}, 0 ,] xrightarrow{p , = , 2} [ , 1, 1, underline{0} ,] xrightarrow{p , = , 1} [ , 0, underline{0}, 1, 0 ,] xrightarrow{p , = , 3} [ , 1, 1, 0, underline{0}, 0 ,] . In the end the sequence b is equal to the sequence a , so this way to perform operations is one of the correct answers. In the second test case, n = 1 and the only achiveable sequence b is [ , 0 , ] . In the third test case, there are six possible sequences of operations: None of them makes b equal to [ , 0, 1, 1 ,] , so the answer is "NO". '...