#include<bits/stdc++.h>
 using namespace  std;
 int main(){
 typedef __int128 ll;
 const int mx=81;
 int n,m,a[mx][mx];
 ll f[mx][mx],sum=0;
 void write(ll x){
     if(x<0)putchar('-'),x=-x;
     if(x>9)write(x/10);
     putchar(x%10+'0');
 	}
 ll solve(int r){
     memset(f,0,sizeof(f));
     for(int i=1;i<=m;i++)f[i][1]=a[r][i]*2;
     for(int j=2;j<=m;j++)for(int i=1;i<=m-j+1;i++)f[i][j]=max(f[i][j-1]+a[r][i+j-1],f[i+1][j-1]+a[r][i])*2;
     return f[1][m];
 }
 int main(){
     cin>>n>>m;
     for(int i=1;i<=n;i++){
         for(int j=1;j<=m;j++)cin>>a[i][j];
         sum+=solve(i);
     }
     write(sum);
     return 0;
 }