#include <iostream>

using namespace std;
int a[17][17];
int n,m,i,j,x,y;
int sum(int a[17][17], int x, int y){
int sum=0;
for (int i=1;i<=n;i++)
    for (int j=1;j<=m;j++)
    if ((x==i)&(y==j)) sum+=a[i][j]; else{
        if ((i==x) || (j==y))

        sum-=a[i][j]; else sum+=a[i][j];}
    return sum;
    }


int main()
{
ifstream f("flip.in");
ofstream g("flip.out");

    f>>n>>m;
   for (i=1;i<=n;i++)
    for (j=1;j<=m;j++) f>>a[i][j];
int maxim=0;
for (i=1;i<=n;i++)
    for (j=1;j<=m;j++)
for (x=1;i<=n;i++)
    for (y=1;j<=m;j++)

        if (maxim <sum(a,x,y)) maxim=sum(a,x,y);




 g<<maxim << endl;
    return 0;
}