#include <stdio.h>
int m,n,i,j,st[18];
long a[17][17],s,max;
FILE *f=fopen("flip.in","r"),*g=fopen("flip.out","w");
void back(int k)
{
	if (k==m)
	{
		s=0;
		int rez=0;
		for (i=0;i<n;++i)
		{
			s=0;
			for (j=0;j<m;++j)
			{	
			s=s+st[j]*a[i][j];
			}
			if (s<0) s=s*(-1);
			rez=rez+s;
		}
		if (rez>max) max=rez;
	}
	else
	{
		st[k]=1;
		back(k+1);
		st[k]=-1;
		back(k+1);
	}

}
int main(void)
{
	fscanf(f,"%d%d",&n,&m);
	for (i=0;i<n;++i)
		for (j=0;j<m;++j)
		{	
			fscanf(f,"%ld",&a[i][j]);
			max=max+a[i][j];
		}
	back(0);
	
	fprintf(g,"%ld\n",max);
	fclose(g);
	return 0;
}