#include <fstream>
#include <algorithm>
using namespace std;
 
ifstream is("flip.out");
ofstream os("flip.in");
 
long n, m,i,j,SMAX=-1,s;
long a[20][20];
void sum(int l,int c)
{
	int fl,fc,s2=0;
	for (fl=0;fl<n;fl++)
	for (fc=0;fc<m;fc++)
	if ((fl==l)||(fc==c)) s2+=(-1)*a[fl][fc];
					else s2+=a[fl][fc];
	if (s2>SMAX) SMAX=s2;
}

 
int main()
{
    is >> n >> m;
    for (i = 0; i <n; i++ )
        for (j = 0; j < m; j++ ){
            is >> a[i][j];
            }
    for (i=0;i<n;i++)
    for (j=0;j<m;j++)
    sum(i,j);
    os << SMAX;
    is.close();
    os.close();
    return 0;
}