#include <iostream>

#include <cstdio>

using namespace std;

int date[][];

int dp[][];

int dir[][]= {{,},{,-},{,},{-,}};

int r,c;

int dpac(int i,int j)

{

    if (dp[i][j]>) return dp[i][j];

    for (int k=; k<; k++)

    {

        int nr=i+dir[k][];

        int nc=j+dir[k][];

        if (nr<||nc<||nr>r||nc>c) continue;

        if (date[i][j]>date[nr][nc])

        {

           dp[nr][nc]=dpac(nr,nc);

           dp[i][j]=max(dp[nr][nc]+,dp[i][j]);

        }

    }

    return dp[i][j];

}

int main()

{

    while (scanf("%d %d",&r,&c)!=EOF)

    {

        int i,j,k,p;

        for (i=; i<=r; i++)

        {

            for (j=; j<=c; j++)

            {

                scanf("%d",&date[i][j]);

                dp[i][j]=;

            }

        }

        int ans=;

        for (i=; i<=r; i++)

        {

            for (j=; j<=c; j++)

            {

                int temp=dpac(i,j);

                if (ans<temp) ans=temp;

            }

        }

        printf("%d\n",ans);

    }

    return ;

}