#include
     
      #include
      
       using namespace std;int n,m,d;int t[4][2]={0,1,0,-1,1,0,-1,0},vist[510][510];int mx,my;char s[510][510];struct ss{	friend bool operator<(const ss a,const ss b)	{		return a.sum>b.sum;	}	int x,y,sum;};priority_queue
       
        Q;void bfs(){	memset(vist,0,sizeof(vist));	ss node1,node2;	node1.x=mx;	node1.y=my;	node1.sum=0;	while(!Q.empty())		Q.pop();	Q.push(node1);	vist[mx][my]=1;	while(!Q.empty())	{		node1=Q.top();		Q.pop();		if(node1.x==0||node1.y==0||node1.x==n-1||node1.y==m-1)		{			printf("%d\n",node1.sum+1);			return ;		}		for(int i=0;i<4;i++)		{			int xx=node1.x+t[i][0];			int yy=node1.y+t[i][1];			if(xx>=0&&xx
        
         =0&&yy