> #include <iostream>
> using namespace std;
> int pmap[101][101],n,m,p,times,resn,resm;
> void getnum(int n,int m,int t) //n行，m列 
> {
> 	switch(t)
> 	{
> 		case 1: {
> 			resn=n-1;resm=m;
> 			break;
> 		}
> 		case 2: {
> 			resn=n;resm=m-1;
> 			break;
> 		}
> 		case 3: {
> 			resn=n+1;resm=m;
> 			break;
> 		} 
> 		case 4:{
> 			resn=n;resm=m+1;
> 		}
> 	} 
> }
> int gettimes(int hang,int lie)
> {
> 	//cout<<"pos:"<<hang<<" "<<lie<<endl; 
> 	times++;
> 	int nownum=pmap[hang][lie],pmin=pmap[hang][lie],pmax=0,ph=102,pl=102,bh=102,bl=102,n;
> 	for(int i=1;i<5;i++)
> 	{
> 		getnum(hang,lie,i);
> 		int nn[]={resn,resm};
> 		if(nn[0]<0 || nn[1]<0) continue;
> 		//cout<<"t:"<<times<<" "<<nn[0]<<" "<<nn[1]<<" "<<i<<endl;
> 		if(pmap[nn[0]][nn[1]]>pmax && pmap[nn[0]][nn[1]]<nownum) 
> 		{
> 			pmax=pmap[nn[0]][nn[1]];
> 			bh=nn[0];
> 			bl=nn[1];
> 		}
> 		if(pmap[nn[0]][nn[1]]<pmin)
> 		{
> 			pmin=pmap[nn[0]][nn[1]];
> 			ph=nn[0];
> 			pl=nn[1];
> 		}
> 	}
> 	if(pmin==10001 ||(ph==102 && pl==102) ||(bh==102 && bl==102) || pmax==0) return times;
> 	//cout<<"re"<<endl; 
> 	gettimes(bh,bl);
> }
> int main()
> {
> 	int tto;
> 	cin>>m>>n;
> 	for(int i=0;i<m;i++) //行 
> 	{
> 		for(int j=0;j<n;j++) 
> 		{ //列 
> 			cin>>p;
> 			pmap[i][j]=p; //前为行，后为列 
> 		}
> 	}
> 	//cout<<pmap[4][4];
> 	//cin>>tto;
> 	//getnum(0,0,tto);
> 	//cout<<resn<<" "<<resm<<" "<<pmap[resn][resm]<<endl;
> 	int nmax=0,now;
> 	for(int ii=0;ii<m;ii++)
> 	{
> 		//cout<<ii<<endl;
> 		for(int jj=0;jj<n;jj++)
> 		{
> 			times=0;
> 			//cout<<ii<<" "<<jj<<endl;
> 			//cout<<"restarted"<<endl;
> 			now=gettimes(ii,jj);
> 			if(now>nmax) nmax=now;
> 		}
> 	}
> 	cout<<nmax<<endl;
> }