#include <iostream>
#define MAX 101
#define INF 0x7FFFFFFF
using namespace std;
 
typedef struct
{
	int x,y;
	int d;
}point;
 
class tQueue
{
public:
	class linklist
	{
	public:
		linklist* next;
		point value;
		linklist()
		{
			next=0;
		}
	};
	linklist *first,*last;
	int size;
	void add(point p)
	{
		if (size==0)
			first=last=new linklist;
		else
			last=last->next=new linklist;
		last->value=p;
		size++;
	}
	point del()
	{
		point rtn=first->value;
		linklist *tfirst=first;
		first=first->next;
		delete tfirst;
		size--;
		return rtn;
	}
	void reset()
	{
		size=0;
		first=last=0;
	}
	tQueue()
	{
		reset();
	}
};
 
bool balk[MAX][MAX];
int F[MAX][MAX][4]; //0上 1下 2左 3右
int dx[4]={-1,1,0,0},dy[4]={0,0,-1,1};
int N,Ans=INF;
point S,T;
tQueue Q;
 
void init()
{
	int i,j,k;
	char c;
	freopen("obstacle.in","r",stdin);
	freopen("obstacle.out","w",stdout);
	cin >> N;
	for (i=1;i<=N;i++)
	{
		while ((c=cin.get())==10 || c==13);
		cin.putback(c);
		for (j=1;j<=N;j++)
		{
			c=cin.get();
			if (c=='x')
				balk[i][j]=true;
			if (c=='A')
				S.x=i,S.y=j;
			if (c=='B')
				T.x=i,T.y=j;
			for(k=0;k<4;k++)
				F[i][j][k]=INF;
		}
	}
}
 
inline bool inrange(point P)
{
	return P.x>=1 && P.x<=N && P.y>=1 && P.y<=N;
}
 
void bfs()
{
	int k,inc;
	point i,j;
	for (k=0;k<4;k++)
	{
		S.d=k;
		F[S.x][S.y][S.d]=0;
		Q.add(S);
	}
	while (Q.size)
	{
		i=Q.del();
		for (k=0;k<4;k++)
		{
			if (k==i.d)
				inc=0;
			else
				inc=1;
			j.d=k;
			j.x=i.x+dx[k];
			j.y=i.y+dy[k];
			if (inrange(j) && !balk[j.x][j.y])
			{
				if (F[i.x][i.y][i.d] + inc < F[j.x][j.y][k])
				{
					F[j.x][j.y][k]=F[i.x][i.y][i.d] + inc;
					if (j.x!=T.x || j.y!=T.y)
						Q.add(j);
					else if (F[j.x][j.y][k]<Ans)
						Ans=F[j.x][j.y][k];
				}
			}
		}
	}
}
 
int main()
{
	init();
	bfs();
	cout << Ans << endl;
	return 0;
}