#include<bits/stdc++.h>
using namespace std;
struct as{
	int x,y,fx; 
}z[10010],q1,q2;
int t=0,w=0,s1,s2,n;
int z1,z2;
bool b[101][101];
int f[101][101];
char Map[101][101];
int fx1[4]={1,-1,0,0};
int fx2[4]={0,0,1,-1};
void push(int x,int y,int fx){
	b[x][y]=1;
	q1.x=x,q1.y=y,q1.fx=fx;
	z[t++]=q1;
}
as top(){
	return z[w++];
}
int Fx(int x1,int y1,int x2,int y2){//←1↓2→3↑4 
	if(x1<x2)return 1;
	else if(x1>x2)return 3;
	else if(y1<y2)return 4;
	else return 2;
}
void In(){
	cin>>n;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cin>>Map[i][j];
			if(Map[i][j]=='A')s1=i,s2=j;
			if(Map[i][j]=='B')z1=i,z2=j;
		}
	}
}
void Work(){
	memset(f,0x3f,sizeof(f));
	push(s1,s2,0);
	f[s1][s2]=0;
	while(t-w>0){
		q2=top();
		int x=q2.x,y=q2.y,fx=q2.fx;
//		cout<<x<<" "<<y<<" "<<f[x][y]<<endl;
		for(int i=0;i<4;i++){
			int u=x+fx1[i],v=y+fx2[i];
			int fxt=Fx(x,y,u,v);
			if(u>=1&&u<=n&&v>=1&&v<=n){
				if(Map[u][v]!='x'&&!b[u][v]){
					b[u][v]=1;
					push(u,v,fxt);
					if(fxt==fx){
						if(f[u][v]>f[x][y])f[u][v]=f[x][y];
					}else{
						if(f[u][v]>f[x][y]+1)f[u][v]=f[x][y]+1;
					}
				}
			}
		}
	}
	cout<<f[z1][z2]-1<<endl;
}
int main(){
	In();
	Work();
	return 0;
}