#include <fstream.h>

//using namespace std;

#define DimMax 17
#define DimMin -1000000

ofstream fout("flip.out");

int s,V[DimMax][DimMax], smax = DimMin, op[DimMax], n, m;

void citire();
void surse();
void bck(int);

int main()
{
	citire();
	bck(1);

	fout<<smax<<"\n";
	fout.close();
	return 0;
}

void citire()
{
	ifstream fin("flip.in");

	fin>>m>>n;

	for (int i=1; i<=m; i++)
	  for (int  j=1; j<=n; j++)
		  fin>>V[i][j];

	fin.close();
}

void bck(int k)
{
    if (k==n+1) surse();
	else 
	{
	   op[k] = 1; bck(k+1);
	   op[k] = -1; bck(k+1);
	}
}

void surse()
{  
    int i,j,x; 

	for(i=1,s=0;i<=m;i++){          
		for(j=1,x=0;j<=n;j++)               
			x+=op[j]*V[i][j];
        if(x>0) s+=x;  
        else s+=-x;  
    }  
    if(s>smax) smax=s;

}