#include<bits/stdc++.h>
using namespace std;
char a[110][110];
int n,aaa,b,aa,bb;
int t,l;
int dx[4]={1,0,0,-1};
int dy[4]={0,1,-1,0};
int bj=1;
int use[110][110];
int minn=1e9;
void dfs(int x,int  y,int ans=0){
	if(x==aa&&y==bb){
		if(ans<minn){
			minn=ans;
			return;
		}
	}
	for(int i=0;i<4;i++){
		int xx=dx[i]+x;
		int yy=dy[i]+y;
		if(use[xx][yy]==0&&xx>=1&&yy>=1&&xx<=n&&yy<=n&&a[xx][yy]!='x'){
			use[xx][yy]=1;
			if(t==dx[i]&&l==dy[i])
			dfs(xx,yy,ans);
			else if(t!=dx[i]||l!=dy[i]){
				t=dx[i],l=dy[i];
				dfs(xx,yy,ans+1);
			}
		}
	}
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cin>>a[i][j];
			if(a[i][j]=='A')
			aaa=i,b=j;
			if(a[i][j]=='B')
			aa=i,bb=j;
		}
	}
	dfs(aaa,b,0);
	minn--;
	cout<<minn;
return 0;
}

样例过了，但全挂