/**
 * Write a description of class PF here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */

import java.io.*;
import java.util.*;



public class PF
{
    public static int shortest;
    public static int numFrames;
    public static char grid[][][];
    public static int Ax, Ay, Bx, By;
    
    
    public static void main (String[] args){
        
    try{
    File srcFile = new File("DATA5.txt"); 
    BufferedReader in = new BufferedReader(new FileReader(srcFile)); 
    File dstFile = new File("OUT5.txt"); 
    PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(dstFile)));
    for (int i = 0; i < 5; i++)
    {
        
        shortest = 1000;
        numFrames = Integer.parseInt(in.readLine());
        grid = new char[numFrames][5][5];
        for (int frame = 0; frame < numFrames; frame++)
        {
            for (int y = 0; y < 5; y++)
            {
                String row = in.readLine();
                for (int x = 0; x < 5; x++)
                {
                    grid[frame][x][y] = row.charAt(x);
                    
                        if (row.charAt(x) == 'A')
                        {
                            Ax = x; Ay = y;
                        }                    
                }
            
            }
        }
           
         recurse(0, Ax, Ay);
         out.print(shortest);
         if (i < 4)
         out.println("");
         
        
    }
    out.close();
    }
     catch(Exception e)     
    {
        System.out.println("error");
    }
}
    
    public static void recurse(int frameNumber, int x, int y)
    {
        if (shortest > frameNumber)
        {
            
            if (grid[frameNumber][x][y] == 'B')
                shortest = frameNumber;
        if (frameNumber+1 < numFrames)
        {
            
            if ( y < 4){
            //up
            if (grid[frameNumber+1][x][y+1] != '#')
            {
                recurse(frameNumber+1,x,y+1);
                
            }}
            
            if (   y > 0){
            //down
            if (grid[frameNumber+1][x][y-1] != '#')
            {
                recurse(frameNumber+1,x,y-1);
            }}
            
            if (  x < 4){
            //right
            if (grid[frameNumber+1][x+1][y] != '#')
            {
                recurse(frameNumber+1,x+1,y);
            }}
            
            if (  x > 0){
            //left
            if (grid[frameNumber+1][x-1][y] != '#')
            {
                recurse(frameNumber+1,x-1,y);
            }}
            
           
        }}
    }

}