#include <iostream>
#include <vector>
#include <algorithm>
#include <array>
#include <iterator>
#include <string>
#include <cctype>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <cmath>
#include <ctime>
#include <iomanip>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <bitset>
#include <random>
#include <utility>
#include <functional>
using namespace std;
void Main()
{
	int H,W;
	cin >> H >> W;
	vector<vector<int>> A(H,vector<int>(W));
	for(int i = 0;i < H;i++)
	{
		for(int j = 0;j < W;j++)
		{
			cin >> A[i][j];
		}
	}
	vector<vector<int>> dp(H,vector<int>(W,-1));
	const int d[5] = {0,1,0,-1};
	auto dfs = [&](auto dfs,int i,int j) -> int
	{
		if(dp[i][j] != -1)
		{
			return dp[i][j];
		}
		int res = 0;
		for(int k = 0;k < 4;k++)
		{
			int ni = i + d[k];
			int nj = j + d[k + 1];
			if(ni < 0 || nj < 0 || ni >= H || nj >= W || A[ni][nj] >= A[i][j])
			{
				continue;
			}
			res = max(res,dfs(dfs,ni,nj) + 1);
		}
		return dp[i][j] = res;
	};
	int ans = 0;
	for(int i = 0;i < H;i++)
	{
		for(int j = 0;j < W;j++)
		{
			ans = max(ans,dfs(dfs,i,j));
		}
	}
	ans++;
	cout << ans << "\n";
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int tt = 1;
	/* cin >> tt; */
	while(tt--) Main();
}