#include<stdio.h>
long int a[17][17],doila[17],cod,k,p,sl,nl,nc,i,j,sm,sc;//65535
int main()
{
	FILE *f,*g;
	f=fopen("flip.in","r");
	g=fopen("flip.out","w");
	fscanf(f,"%d%d",&nl,&nc);
	for(i=0;i<nl;i++)
	for(j=0;j<nc;j++)
	fscanf(f,"%ld",&a[i][j]);
	doila[0]=1;
	for(i=1;i<nc;i++)
	 doila[i]=doila[i-1]*2;
	k=doila[nc-1];
	for(p=0;p<k;p++)
	{ sc=0;
	  for(i=0;i<nl;i++)
	  {sl=0;cod=p;
	   for(j=0;j<nc;j++)
	   { sl+=(2*(cod%2)-1)*a[i][j];cod/=2;}
	   if(sl<0)sl=-sl;sc+=sl;
	  }
	  if(sc>sm)sm=sc;
	}
	fprintf(g,"%ld\n",sm);
	fclose(f);
	return 0;
}