#include <bits/stdc++.h>
using namespace std;
int R,C,a[101][101],num[101][101]={0},M=0;
bool check(int nx,int ny)
{
	return 1<=nx && nx<=R && 1<=ny && ny<=C;
}
int Maxnum(int sx,int sy)
{
	if(num[sx][sy]>0)
	  return num[sx][sy];
	int ans=0;
	const int dx[5]={0,0,0,1,-1},dy[5]={0,1,-1,0,0};
	for(int i=1;i<=4;i++)
	  {
	  	int nx=sx-dx[i],ny=sy-dy[i];
	  	if(!check(nx,ny)) continue;
	  	if(a[nx][ny]>=a[sx][sy]) continue;
	  	int t=Maxnum(nx,ny);
	  	if(ans<t)
	  	  ans=t;
	  }
	num[sx][sy]=ans+1;
	return ans+1;
}
int main()
{
	freopen("a.in","r",stdin);
	freopen("a.out","w",stdout);
	scanf("%d%d",&R,&C);
	for(int i=1;i<=R;i++)
	  for(int j=1;j<=C;j++) scanf("%d",&a[i][j]);
	for(int i=1;i<=R;i++)
	  for(int j=1;j<=C;j++)
	    {
	      Maxnum(i,j);
	      if(M<num[i][j]) M=num[i][j];
	    }
	printf("%d",M);
	fclose(stdin);
	fclose(stdout);
	return 0; 
}