rt

#include<bits/stdc++.h>
using namespace std;
int z[105][105],ans[105][105];
pair<int,int> q[10005];
bool F(pair<int,int> x,pair<int,int> y)
{
	return x.first<=y.first;
}
int main()
{
	int n,r,c,i,j,p=0,maxn=0;
	cin>>r>>c;
	n=r*c;
	for (i=1;i<=r;i++)
	{
		for (j=1;j<=c;j++)
		{
			cin>>z[i][j];
			q[++p].first=z[i][j];
			q[p].second=i*c-c+j;
		}
	}
	sort(q+1,q+n+1,F);
	for (i=1;i<=n;i++)
	{
		int a,b,s;
		s=q[i].second;
		b=s%c;
		if (b==0) b=c;
		a=(s-b)/c+1;
		if (z[a-1][b]<z[a][b]) ans[a][b]=max(ans[a][b],ans[a-1][b]);
		if (z[a+1][b]<z[a][b]) ans[a][b]=max(ans[a][b],ans[a+1][b]);
		if (z[a][b-1]<z[a][b]) ans[a][b]=max(ans[a][b],ans[a][b-1]);
		if (z[a][b+1]<z[a][b]) ans[a][b]=max(ans[a][b],ans[a][b+1]);
		ans[a][b]++;
	}
	for (i=1;i<=r;i++)
	{
		for (j=1;j<=c;j++)
		{
			maxn=max(maxn,ans[i][j]);
		}
	}
	cout<<maxn;
    return 0;
}