#include <stdio.h>

using namespace std;
FILE *f,*g;
int max1,n,m,a[17][17],x[17];
void verif ()
{   int y; int s1=0,s=0;
    for (int j=1;j<=m;j++)
    {
        s=0;
        for (int i=1;i<=n;i++)
    {
        y=a[i][j];
        if (x[i]==0) y=0-y;
        s+=y;
    }
        if (s<0) s=0-s;
        s1+=s;
    }
    if (s1>max1) max1=s1;
}
void back (int k)
{
    for (int i=0;i<=1;i++)
    {

         x[k]=i;
        if (k==n) verif ();
         else back (k+1);

    }
}
int main()
{f=fopen ("flip.in","r");
 g=fopen ("flip.out","w");
 fscanf (f,"%d%d",&n,&m);
 for (int i=1;i<=n;i++)
     for (int j=1;j<=m;j++) fscanf (f,"%d",&a[i][j]);
back (1);
fprintf (g,"%d",max1);

    return 0;
}