CF1926F.Vlad and Avoiding X

Vladislav has a grid of size $7 \times 7$, where each cell is colored black or white. In one operation, he can choose any cell and change its color (black $\leftrightarrow$ white).

Find the minimum number of operations required to ensure that there are no black cells with four diagonal neighbors also being black.

The left image shows that initially there are two black cells violating the condition. By flipping one cell, the grid will work.

弗拉迪斯拉夫有一个 $7 \times 7$ 的网格，每个格子被染成黑色或白色。在一次操作中，他可以选择任意一个格子并翻转其颜色（黑 $\leftrightarrow$ 白）。

求保证不存在“某个黑色格子，其四个对角方向的邻居也均为黑色”的最小操作次数。

左侧图像显示初始时有两个黑色格子违反该条件。通过翻转一个格子，即可使整个网格满足要求。

The first line of input contains a single integer $t$ ($1 \leq t \leq 200$) — the number of test cases. Then follows the description of the test cases.

Each test case consists of $7$ lines, each containing $7$ characters. Each of these characters is either $\texttt{W}$ or $\texttt{B}$, denoting a white or black cell, respectively.

输入的第一行包含一个整数 $t$（$1 \leq t \leq 200$），表示测试用例的数量。随后是各测试用例的描述。

每个测试用例由 $7$ 行组成，每行包含 $7$ 个字符。每个字符为 $\texttt{W}$ 或 $\texttt{B}$，分别表示白色格子或黑色格子。

For each test case, output a single integer — the minimum number of operations required to ensure that there are no black cells with all four diagonal neighbors also being black.

对于每个测试用例，输出一个整数——确保不存在某个黑色格子，其四个对角线方向的邻居格子也均为黑色，所需的最少操作次数。

The first test case is illustrated in the statement.

The second test case is illustrated below:

In the third test case, the grid already satisfies the condition.

第一个测试用例在题目描述中已给出图示。

第二个测试用例如下图所示：

在第三个测试用例中，网格已满足条件。