B"You have an array a of size n consisting only of zeroes and ones. You can do the following operation: Note that elements of a can become bigger than 1 after performing some operations. Also note that n becomes 1 less after the operation. What is the minimum number of operations needed to make a non-decreasing, i. e. that each element is not less than the previous element? Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 10^4 ). The description of the test cases follows. The first line of each test case contains an integer n ( 1 <= n <= 10^5 ), the size of array a . Next line contains n integers a_{1}, a_{2}, ldots a_{n} ( a_i is 0 or 1 ), elements of array a . It's guaranteed that sum of n over all test cases doesn't exceed 2 cdot 10^5 . For each test case print a single integer, minimum number of operations needed to make a non-decreasing. In the first test case, a is already non-decreasing, so you don't need to do any operations and the answer is 0 . In the second test case, you can perform an operation for i = 1 and j = 5 , so a will be equal to [0, 0, 1, 2] and it becomes non-decreasing. In the third test case, you can perform an operation for i = 2 and j = 1 , so a will be equal to [1] and it becomes non-decreasing. "...