#include <stdio.h>
FILE *f,*g;
long a[17][17],l[17];
long p,o;
int main()
{
  long n,m,i,j,s,k1,k2,smax,semn,sc;
  FILE *f=fopen("flip.in","rt");
  FILE *g=fopen("flip.out","wt");
  fscanf(f,"%ld %ld",&n,&m);
  for (i=1;i<=n;i++)
	for (j=1;j<=m;j++)
	  fscanf(f,"%ld",&a[i][j]);
  smax=0;
  l[n]=-1;
  do
   {
	 i=n;
	 l[i]++;
	 while (l[i]>1)
	   {
	  l[i-1]++;
	  l[i]=0;
	  i--;
	   }
	 j=m;
	 s=0;
	 for (k1=1;k1<=m;k1++)
	   {
		 sc=0;
		 for (k2=1;k2<=n;k2++)
		   {
		 if (l[k2]==1)
		   semn=-1;
		  else
		   semn=1;
			 sc+=a[k2][k1]*semn;
		   }
		 if (sc<0)
		   sc*=-1;
		 s+=sc;
	   }
	 if (s>smax)
	   smax=s;
   }
  while (!l[0]);
  fprintf(g,"%ld\n",smax);
  fclose(f);
  fclose(g);
  return 0;
}