#include<fstream.h>
#include <iostream.h>
#define L_MAX 15
int n,sol[L_MAX],m,a[L_MAX][L_MAX],max,s,j,i;
void solve ()
{
 int s=0,j,i;
 for(j=1;j<=m;++j)
     {
      int sc=0;
    for(i=1;i<=n;++i)
  sc+=sol[i]*a[i][j];
	if(sc<0)
      s+=(-sc);
    else
	 s+=sc;
       }
	   if(s>max)
	max=s;
	}
	void back (int k)
	{
      int val;
   if(k==n+1)
       solve();
     else
  for(val=-1;val<=1;val+=2)
       {
     sol[k]=val;
   back (k+1);
	}
       }
	int main ()
	{
    ifstream in("flip.in");
    ofstream out("flip.out");
	in>>n>>m;
	for(i=1;i<=n;++i)
           for(j=1;j<=m;++j)
		       {
					in>>a[i][j];
					s+=a[i][j];
			    }
			max=s;
			back (1);
			printf("%d",max);
			return 0;
}