#include <bits/stdc++.h>
using namespace std;
#define __int28 int
int map2[80][80];
int f[80][80];
int n,m,ans=0;
inline __int28 read(){
	char c=getchar();int x=0,f=1;
	while (c<'0'||c>57){
		if (c=='-'){
			f=-1;
		}
		c=getchar();
	}
	while (c>='0'&&c<='9'){
		x=x*10+c-48;
		c=getchar();
	}
	return x*f;
}
void write(__int28 x){
	if (x<0){
		putchar('-');
		x=-x;
	}
	if (x>10){
		write(x/10);
	}
	putchar(x%10+'0');
}
int main(){
	n=read();m=read();
	for (register int i=0;i<n;i++){
		for (register int j=0;j<m;j++){
			map2[i][j]=read();
		}
	}
	for (register int i=0;i<n;i++){
		memset(f,0,sizeof(f));
		for (register int q=0;q<m;q++){
			for (register int j=0;j+q<m;j++){
				f[j][j+q]=max(2*map2[i][j]+2*f[j+1][j+q],2*map2[i][j+q]+2*f[j][j+q-1]);
			}
		}
		ans+=f[0][m-1];
	}
	write(ans);
	return 0;
} 

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