#include <fstream>
using namespace std;
int a[20][20],v[20],smax,n,m;

void tipar(){
	int i,j,max=0,s;
	for(i=1;i<=n;i++)
		{	s=0;
		for(j=1;j<=m;j++)
			 s+=a[i][j]*v[j];
		if(s>0)
			max+=s;
		else 
			max-=s;
		}
	if(smax<max)
	smax=max;	
	
}

void bkt(int k)
{
	if(k>m)
		tipar();
	else {
		v[k]=-1;
		bkt(k+1);
		v[k]=1;
		bkt(k+1);	
	}
}

int main(){
	ifstream in("flip.in");
	ofstream out("flip.out");
	int i,j;
	in>>n>>m;
	for(i=1;i<=n;i++)
		for(j=1;j<=m;j++)
			{in>>a[i][j];smax+=a[i][j];}
	bkt(1);
	out<<smax;
	in.close();
	out.close();
	return 0;
}