B"You are given a square grid with n rows and n columns. Each cell contains either 0 or 1 . In an operation, you can select a cell of the grid and flip it (from 0 to 1 or 1 to 0 ). Find the minimum number of operations you need to obtain a square that remains the same when rotated 0^{ circ} , 90^{ circ} , 180^{ circ} and 270^{ circ} . The picture below shows an example of all rotations of a grid. The first line contains a single integer t ( 1 <= q t <= q 100 ) -- the number of test cases. The first line of each test case contains a single integer n ( 1 <= q n <= q 100 ) -- the size of the grid. Then n lines follow, each with n characters a_{i,j} ( 0 <= q a_{i,j} <= q 1 ) -- the number written in each cell. For each test case output a single integer -- the minimum number of operations needed to make the square look the same rotated 0^{ circ} , 90^{ circ} , 180^{ circ} and 270^{ circ} . In the first test case, we can perform one operations to make the grid begin{matrix}0 & 1 & 0 1 & 1 & color{red}{1} 0 & 1 & 0 end{matrix} . Now, all rotations of the square are the same. In the second test case, all rotations of the square are already the same, so we don't need any flips. "...