// Crazy King

import java.util.Scanner;

public class Solution {
	static int[] X = new int[10000000];
	static int[] Y = new int[10000000];
	static int[] T = new int[10000000];
	static int l, r;
	static int[][] Ts;
	static int[] Dx = {0, 0, -1, 1, -1, -1, 1, 1};
	static int[] Dy = {-1, 1, 0, 0 ,-1, 1, -1, 1};
	static int[] Mx = {-2, -2, -1, -1, 2, 2, 1, 1};
	static int[] My = {-1, 1, -2, 2, -1, 1, -2, 2};
	static char[][] A;
	static boolean[][] Check;

	public static void main(String[] args)  {
		//System.setIn(new FileInputStream("king.txt"));
		Scanner sc = new Scanner(System.in);
		int testCase = sc.nextInt();
		for (int tc = 1; tc <= testCase; tc++) {
			int col = sc.nextInt() + 4;
			int row = sc.nextInt() + 4;
			A = new char[row][col];
			Ts = new int[row][col];
			for (int i = 0; i < A.length; i++) {
				A[i][0] = 'Z'; Ts[i][0] = -1;
				A[i][1] = 'Z';	Ts[i][1] = -1;
				A[i][A[0].length - 1] = 'Z'; Ts[i][A[0].length - 1] = -1;
				A[i][A[0].length - 2] = 'Z';	Ts[i][A[0].length - 2] = -1;
			}
			for (int i = 0; i < A[0].length; i++) {
				A[0][i] = 'Z';
				A[1][i] = 'Z';
				A[A.length - 1][i] = 'Z';
				A[A.length - 2][i] = 'Z';
				Ts[0][i] = -1;
				Ts[1][i] = -1;
				Ts[A.length - 1][i] = -1;
				Ts[A.length - 2][i] = -1;
			}
			l = -1; r = -1;
			
			Check = new boolean[row][col];
			int vuaX = 0, vuaY = 0;
			for (int i = 2; i < A.length - 2; i++) {
				String s = sc.next();
				for (int j = 2; j < A[0].length - 2; j++) {
					A[i][j] = s.charAt(j - 2);
					if(A[i][j] == 'Z') {
						push(i, j, 1);
					}
					if(A[i][j] == 'A') {
						vuaX = i;
						vuaY = j;
						Check[i][j] = true;
					}
				}
			}
			

			nguaLan();


			int res = 0;
			l = -1; r = -1;
			pushVua(vuaX, vuaY, 1);
			int k = 0;
			while(l != r) {
				int x = X[++l];
				int y = Y[l];
				int t = T[l];
				for (int i = 0; i < 8; i++) {
					int dx = x + Dx[i];
					int dy = y + Dy[i];
					if(A[dx][dy] == 'B') {
						res = t + 1;
						k = 1;
						break;
					}
					if(A[dx][dy] == '.' && !Check[dx][dy]) {
						Check[dx][dy] = true;
						pushVua(dx, dy, t + 1);
					}
				}
				if(res != 0) break;
			}
			if(k == 0) res = 0;
			
			System.out.println(res - 1);
		}
	}
	
	static void pushVua(int x, int y, int t) {
		X[++r] = x;
		Y[r] = y;
		T[r] = t;
	}
	
	static void nguaLan() {
		while(l != r) {
			int x = X[++l];
			int y = Y[l];
			int t = T[l];
			for (int i = 0; i < 8; i++) {
				int mx = x + Mx[i];
				int my = y + My[i];
				if(A[mx][my] == '.' ) {					
					A[mx][my] = 'Z';
				}
			}
		}
	}
	
	static void push(int x, int y, int t) {
		X[++r] = x;
		Y[r] = y;
		T[r] = t;
	}
	

}

Line 3: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'java'
Line 5: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'class'