#include<fstream>
using namespace std;
int a[20][20],i,m,n,s;
ifstream f("flip.in");
ofstream d("flip.out");
int main(){
long i,j,s1,r,t;
f>>n;
f>>m;
  for (i=0;i<n;i++)
    for (j=0;j<m;j++)
        f>>a[i][j];

for (r=0;r<(1<<m);r++)
    {
    s1=0;
    for (i=0;i<n;i++)
        {
        for (t=j=0;j<m;j++)
            if (r&(1<<j))t+=-a[i][j];
            else t+=a[i][j];
        if (t>-t)s1+=t;
        else s1+=-t;
        }
    if (s1>s)s=s1;
    }
d<<s;
return 0;
}