Description: There is a grid with $$$n$$$ rows and $$$m$$$ columns. Some cells are colored black, and the rest of the cells are colored white. In one operation, you can select some black cell and do exactly one of the following: - color all cells in its row black, or - color all cells in its column black. You are given two integers $$$r$$$ and $$$c$$$. Find the minimum number of operations required to make the cell in row $$$r$$$ and column $$$c$$$ black, or determine that it is impossible. Input Format: The input consists of multiple test cases. The first line contains an integer $$$t$$$ ($$$1 \leq t \leq 100$$$) — the number of test cases. The description of the test cases follows. The first line of each test case contains four integers $$$n$$$, $$$m$$$, $$$r$$$, and $$$c$$$ ($$$1 \leq n, m \leq 50$$$; $$$1 \leq r \leq n$$$; $$$1 \leq c \leq m$$$) — the number of rows and the number of columns in the grid, and the row and column of the cell you need to turn black, respectively. Then $$$n$$$ lines follow, each containing $$$m$$$ characters. Each of these characters is either 'B' or 'W' — a black and a white cell, respectively. Output Format: For each test case, if it is impossible to make the cell in row $$$r$$$ and column $$$c$$$ black, output $$$-1$$$. Otherwise, output a single integer — the minimum number of operations required to make the cell in row $$$r$$$ and column $$$c$$$ black. Note: The first test case is pictured below. We can take the black cell in row $$$1$$$ and column $$$2$$$, and make all cells in its row black. Therefore, the cell in row $$$1$$$ and column $$$4$$$ will become black. In the second test case, the cell in row $$$2$$$ and column $$$1$$$ is already black. In the third test case, it is impossible to make the cell in row $$$2$$$ and column $$$2$$$ black. The fourth test case is pictured below. We can take the black cell in row $$$2$$$ and column $$$2$$$ and make its column black. Then, we can take the black cell in row $$$1$$$ and column $$$2$$$ and make its row black. Therefore, the cell in row $$$1$$$ and column $$$1$$$ will become black.