#include <iostream>
#include <cstdio>
using namespace std;

const int maxn = 110;

int gra[maxn][maxn];
int record[maxn][maxn];

int R, C;

bool inner(int x, int y)
{
    return x>=1&&x<=R&&y>=1&&y<=C;
}

int getMax(int x, int y)
{
    if(record[x][y])
        return record[x][y];
    int maxx = 0;
    if(inner(x+1,y)&&(gra[x+1][y]<gra[x][y])) maxx = max(maxx, getMax(x+1,y));
    if(inner(x-1,y)&&(gra[x-1][y]<gra[x][y])) maxx = max(maxx, getMax(x-1,y));
    if(inner(x,y+1)&&(gra[x][y+1]<gra[x][y])) maxx = max(maxx, getMax(x,y+1));
    if(inner(x,y-1)&&(gra[x][y-1]<gra[x][y])) maxx = max(maxx, getMax(x,y-1));
    return record[x][y] = 1 + maxx;
}

int main()
{
    while(scanf("%d%d",&R,&C)!=EOF)
    {
        for(int i=1;i<=R;i++)
        {
            for(int j=1;j<=C;j++)
            {
                scanf("%d",&gra[i][j]);
                record[i][j] = 0;
            }
        }
        int res = 0;
        for(int i=1;i<=R;i++)
        {
            for(int j=1;j<=C;j++)
            {
                res = max(res, getMax(i,j));
            }
        }
        cout<<res<<endl;
    }
    return 0;
}