#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int h, w;
    cin >> h >> w;
    vector<vector<int>> dp(h, vector<int>(w, -1)), A(h, vector<int>(w));
    auto rec = [&](auto rec, int y, int x) -> int {
        if(dp[y][x] != -1) return dp[y][x];
        dp[y][x] = 1;
        for(int i = 0; i < 4; i++){
            int ny = y + (i == 0) - (i == 1);
            int nx = x + (i == 2) - (i == 3);
            if(ny < 0 || nx < 0 || ny >= h || nx >= w) continue;
            if(A[y][x] < A[ny][nx]) dp[y][x] = max(dp[y][x], rec(rec, ny, nx) + 1);
        }
        return dp[y][x];
    };
    for(int y = 0; y < h; y++){
        for(int x = 0; x < w; x++){
            cin >> A[y][x];
        }
    }
    int ans = 0;
    for(int y = 0; y < h; y++){
        for(int x = 0; x < w; x++){
            ans = max(ans, rec(rec, y, x));
        }
    }
    cout << ans << '\n';
}