#include<bits/stdc++.h>
using namespace std;
int dx[]={-1,1,0,0};
int dy[]={0,0,-1,1};
const int N=110;
char g[N][N];
int dist[N][N];
struct Node{
    int x,y;
};
int n,sx,sy,ex,ey;
bool check(int x,int y)
{
    if(x<1||x>n||y<1||y>n)
    {
        return false;
    }
    if(g[x][y]=='x')
    {
        return false;
    }
    return true;
}
int bfs()
{
    queue<Node> q;
    q.push({sx,sy});
    while(q.size()) 
    {
        Node t=q.front();
        q.pop();
        if(t.x==ex&&t.y==ey)
        {
            return dist[ex][ey];
        }
        for(int i=0;i<4;i++)
        {
            int a=t.x+dx[i];
            int b=t.y+dy[i];
            while(check(a,b))
            {
                if(dist[a][b]>dist[t.x][t.y]+1)
                {
                    dist[a][b]=dist[t.x][t.y]+1;
                    q.push({a,b});
                } 
                a+=dx[i];
                b+=dy[i]; 
            }
        }
    }
} 
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            cin>>g[i][j];
            if(g[i][j]=='A')
            {
                sx=i,sy=j;
            }
            else if(g[i][j]=='B')
            {
                ex=i,ey=j;
            }
        }
    }
    memset(dist,0x3f,sizeof dist);
    dist[sx][sy]=0;
    bfs();
    if(dist[ex][ey]==0x3f3f3f3f)
    {
        cout<<-1;
    }
    else
    {
        cout<<dist[ex][ey]-1;
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
struct Node{
    int x,y;    
};
int n,sx,sy,ex,ey;
const int N=110;
char g[N][N];
int dist[N][N];
int dx[]={-1,1,0,0};
int dy[]={0,0,-1,1};
bool check(int x,int y) //判断出界和不能走 
{
    if(x<1||x>n||y<1||y>n) return false;
    if(g[x][y]=='x') return false;
    return true;
}
int bfs()
{
    queue<Node> q;
    q.push({sx,sy});
    while(q.size()) 
    {
        Node t=q.front();
        q.pop();
        if(t.x==ex&&t.y==ey)
        {
            return dist[ex][ey];
        }
        for(int i=0;i<4;i++)
        {
            int a=t.x+dx[i];
            int b=t.y+dy[i];
            while(check(a,b))
            {
                if(dist[a][b]>dist[t.x][t.y]+1)
                {
                    dist[a][b]=dist[t.x][t.y]+1;
                    q.push({a,b});
                } 
                a+=dx[i];
                b+=dy[i]; 
            }
        }
    }
} 
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            cin>>g[i][j];
            if(g[i][j]=='A') sx=i,sy=j;
            else if(g[i][j]=='B') ex=i,ey=j;
        }
    }
    memset(dist,0x3f,sizeof dist);
    dist[sx][sy]=0;
    bfs();
    if(dist[ex][ey]==0x3f3f3f3f) cout<<-1;
    else cout<<dist[ex][ey]-1;
    return 0;
}