#include<bits/stdc++.h>
using namespace std;
int xx[]={0,-1,0,1};
int yy[]={1,0,-1,0};
int mp[105][105],a[105][105],vis[105][105];
int r,c,temp,maxx,maxy,ans;
int main(){
	cin>>r>>c;
	for(int i=1;i<=r;i++)
		for(int j=1;j<=c;j++){
			cin>>mp[i][j];
			if(mp[i][j]>temp){
				temp=mp[i][j];
				maxx=i;
				maxy=j;
			}
		}			
	queue< int >step;
	queue< int > a;
	queue< int > b;
	step.push(1);
	a.push(maxx);
	b.push(maxy);
	while(!step.empty()){
		for(int i=0;i<4;i++){
			int dx=a.front()+xx[i];
			int dy=b.front()+yy[i];
			if(dx>=1&&dx<=r&&dy>=1&&dy<=c&&(mp[dx][dy]<mp[a.front()][b.front()])){
				a.push(dx);
				b.push(dy);
				step.push(step.front()+1);
				ans=max(ans,step.front());				
			}				
		}
			a.pop();
			b.pop();
			step.pop();	
	
}
	cout<<ans+1<<endl;
	return 0;	
}