#include<stdio.h>
long n,m,a[16][16],st[16],smax;
void back(int k)
{
	int i,j,s,t;
	if(k==m)
	{ s=0;
	for(i=0;i<n;++i)
	 {for(t=j=0;j<m;++j)
	  if(st[j]) t+=-a[i][j];
	  else t+=a[i][j];

	s+=t<-t ? -t : t;
	}
	if(smax<s) smax=s;
	return ;
	}
	st[k]=0; back(k+1);
	st[k]=1; back(k+1);
   }
int main()
{
long i,j;
	freopen("flip.in","r",stdin);
	scanf("%ld %ld",&n,&m);

	for(i=0;i<n;++i)
	 for(j=0;j<m;++j)
	 scanf("%ld",a[i]+j);

	back(0);
	freopen("flip.out","w",stdout);
	printf("%ld\n",smax);


return 0;
}