#include <stdio.h>
#include <stdlib.h>

int i,j,m,n;
long a[16][16],sum,smax,st[16];
void backt(int k);

int main()
{
    FILE *pf,*pfi;
   pf= fopen("flip.in","r");
   pfi=fopen("flip.out","w");

fscanf(pf,"%d %d",&n,&m);

for(i=0;i<n;i++)
    for(j=0;j<m;j++)
    fscanf(pf,"%ld",&a[i][j]);
    backt(0);
fprintf(pfi,"%ld",smax);
return 0;

}
void backt(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;
 backt(k+1);
 st[k]=1;
 backt(k+1);
}