#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ri register ll
ll n,m,a[85];
__int128 ans;
inline void print(__int128 x){
	if(x>9)print(x/10);
	putchar(x%10+'0');
}
inline __int128 dp(){
	__int128 b[81][81];
	for(ri z=0;z<=m;z++){
		for(ri y=1;y+z<=m;y++){
			b[y][y+z]=max(b[y+1][y+z]+a[y],b[y][y+z-1]+a[y+z])*2;
		}
	}
	return b[1][m];
}
signed main(int argv,char**argc) {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>m;
	for(ri z=1;z<=n;z++){
		for(ri y=1;y<=m;y++){
			cin>>a[y];
		}
		ans+=dp();
	}
	print(ans);
	return 0;
}

我觉得我写得好像没有问题啊
还请各位大佬指点指点