#include<bits/stdc++.h>
using namespace std;
int dx[5]={0,0, 0,1,-1};
int dy[5]={0,1,-1,0, 0};
int n,m;
int sx,sy,e1,e2;
int mp[1000][1000];
int vis[1000][1000];
bool Noway(int nx,int ny)
{
	if(nx<1||ny<1||nx>n||ny>n) return true;
	if(vis[nx][ny]==1||mp[nx][ny]==-1) return true;
	return false;
}
struct st
{
	int s,x,y,fa;
	bool operator < (const st &a) const 
	{   
        return s>a.s;
    }
};
int bfs(int x,int y)
{
	priority_queue <st> q;
	st cur;
	cur.s=0;cur.x=x;cur.y=y;cur.fa=100;
	q.push(cur);
	vis[x][y]=1;
	while(!q.empty())
	{
		cur=q.top();
		q.pop();
		if(cur.x==e1&&cur.y==e2)
		{
			return cur.s;
		}
		for(int i=1;i<=4;i++)
		{
			int nx=cur.x+dx[i];
			int ny=cur.y+dy[i];
			if(Noway(nx,ny)) continue;
			vis[nx][ny]=1;
			st nxt;
			nxt.x=nx;
			nxt.y=ny;
			nxt.s=cur.s;
			if(cur.fa!=i) nxt.s++;
			nxt.fa=i;
			q.push(nxt);
		}
	}
	return 0;
}
int main()
{
	cin>>n;
	int i,j;
	for(i=1;i<=n;i++)
	{
		for(j=1;j<=n;j++)
		{
			char t;
			cin>>t;
			if(t=='A') sx=i,sy=j;
			if(t=='B') e1=i,e2=j;
			if(t=='x') mp[i][j]=-1;
		}
	}
	cout<<bfs(sx,sy)-1;
	return 0;
}