package dp;

import java.util.Scanner;

public class Skiing {

static int[][] result;

static int max = 0;

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int m = sc.nextInt();

int n = sc.nextInt();

double[][] a = new double[m][n];

result = new int[m][n];

for(int i=0;i<m;i++){

for(int j=0;j<n;j++){

a[i][j] = sc.nextDouble();

result[i][j]=0;

}

}

for(int i=0;i<m;i++){

for(int j=0;j<n;j++){

result[i][j] = Calculate(a,m,n,i,j);

if(result[i][j]>max){

max = result[i][j];

}

}

}

System.out.println(max);

}

private static int Calculate(double[][] a,int m,int n, int i, int j) {

if(result[i][j]>0){

return result[i][j];

}

int te=0,x;

if(j-1>=0&&a[i][j]>a[i][j-1]){

x=Calculate(a,m,n,i,j-1);

if(x>te){

te =x;

}

}

if(j+1<n&&a[i][j]>a[i][j+1]){

x=Calculate(a,m,n,i,j+1);

if(x>te){

te=x;

}

}

if(i-1>=0&&a[i][j]>a[i-1][j]){

x=Calculate(a,m,n,i-1,j);

if(x>te){

te=x;

}

}

if(i+1<n&&a[i][j]>a[i+1][j]){

x=Calculate(a,m,n,i+1,j);

if(x>te){

te=x;

}

}

return te+1;

}

}