https://www.luogu.org/problemnew/show/P1005

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG

using namespace std;
typedef long long ll;
typedef __int128 lll;
const int N=10000;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m;
lll dp[100][100];
lll ans=0;
void print(__int128 x)
{
    if (x>9) print(x/10);
    putchar('0'+x%10);
}
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++){
        memset(dp,0,sizeof(dp));
        for(int j=1;j<=m;j++){
            scanf("%d",&dp[j][j]);
        }
        for(int j=1;j<m;j++){
            for(int k=1;k<=m-j;k++){
                dp[k][j+k]=max(dp[k+1][j+k]*2+dp[k][k],dp[k][j+k-1]*2+dp[j+k][j+k]);
            }
        }
        ans+=dp[1][m]*2;
    }
    print(ans);
    cout << endl;
    //cout << "Hello world!" << endl;
    return 0;
}