#include<stdio.h>
long long n, m, a[16][16],smax;
void main()
{
  long long i, j, k, s, t;
  freopen("flip.in","r",stdin);
  scanf("%lld %lld",&n, &m);
  for (i=0; i<n; i++)
    for (j=0; j<m; j++) scanf("%lld",a[i]+j);
  for (i=0; i<(1<<m); i++)
    {
      s=0;
      for (k=0; k<n; k++)
	{
	  for (t=j=0; j<m; j++)
	    if (i&(1<<j)) t+=-a[k][j];
	      else t+=a[k][j];
	  s+=t<-t ?-t : t;
	}
      if (smax<s) smax=s;
    }
  freopen("flip.out","w",stdout);
  printf("%lld\n",smax);
}