#include<bits/stdc++.h>
using namespace std;
int n,m;
int a[105][105],f[105][105];
int main(){
	freopen("snow.in","r",stdin);
	freopen("snow.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			scanf("%d",&a[i][j]);
			f[i][j]=1;
		}
	}
	int ans=100;
	while(ans--){
		for(int i=1;i<=n;i++){
			for(int j=1;j<=m;j++){
				if(a[i][j+1]<a[i][j]&&j<m){
					f[i][j]=max(f[i][j],f[i][j+1]+1);
				}
				if(a[i][j-1]<a[i][j]&&j>1){
					f[i][j]=max(f[i][j],f[i][j-1]+1);
				}
				if(a[i-1][j]<a[i][j]&&i>1){
					f[i][j]=max(f[i][j],f[i-1][j]+1);
				}
				if(a[i+1][j]<a[i][j]&&i<n){
					f[i][j]=max(f[i][j],f[i+1][j]+1);
				}
			}
		}
	}
	ans=0;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			ans=max(ans,f[i][j]);
		}
	}
	cout<<ans<<endl;
}