#include<bits/stdc++.h>
//#include<graphics.h>
//#define fo(1,j,k) for(int i=j;i<=k;i++)
using namespace std;
/*
inline int read(){
    int s=0,w=1;
    char ch=getchar();
    while(ch<='0'||ch>'9'){
        if(ch=='-') w=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
*/
int n,m,a[105][105],f[105][105];
int dfs(int x,int y){
	if(x>n || x<1 || y>m || y<1) return 0;
	if(f[x][y]!=-1) return f[x][y];
	int ans=0;
	if(a[x][y]>a[x][y+1]) ans=max(ans,dfs(x,y+1)); 
	if(a[x][y]>a[x][y-1]) ans=max(ans,dfs(x,y-1)); 
	if(a[x][y]>a[x+1][y]) ans=max(ans,dfs(x+1,y)); 
	if(a[x][y]>a[x-1][y]) ans=max(ans,dfs(x-1,y)); 
	return f[x][y]=ans+1;
}
signed main(){
    //freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	//std::ios::sync_with_stdio(false);
	scanf("%d%d",&n,&m);
	sizeof(f,-1,sizeof(f)); 
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            scanf("%d",&a[i][j]);
    int ans=0;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            ans=max(ans,dfs(i,j));
    printf("%d",ans);
	return 0;
}