#include<fstream>
#define dim 17
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");

int n,m,a[dim][dim],s=0, i,j, sol[dim], cur;



void bec(int k);
void calcul ();



int main()
{

		 fin>>n>>m;
		 for(i=1;i<=n;++i)
		   for(j=1;j<=m;++j)
			 {
				   fin>>a[i][j];
				   cur+=a[i][j];
			 }
		 bec(1);
		 fout<<cur;
}
void bec(int k)
{
 		 if(k==n+1)
 		    calcul();
     else
       for(int val=-1;val<=1;val+=2)
       {
	 				 sol[k]=val;
	 				 bec(k+1);
			 }
}
void calcul()
{
 		 int s=0, s1,i,j;
 		 for(j=1;j<=m;++j)
 		 {
				s1=0;
				for(i=1;i<=n;++i)
				  s1+=a[i][j]*sol[i];
		    if(s1<0)
		      s+=(-s1);
        else
          s+=s1;
     }
     if(s>cur)
      cur=s;
}