#include <stdio.h>
#include <values.h>
#define DIMMAX 30
int a[DIMMAX][DIMMAX],inm[2*DIMMAX],smax=0,n,m,max=-300;
void calcul()
{
    int i,j,s=0,smax=0;
    for(i=1; i<=n; ++i)
       { 
         s=0;
             for(j=1; j<=m; ++j)
                 s+=a[i][j]*inm[j];
        if(s<0) s*=-1;
        smax+=s;
       }             
      if(max<smax) max=smax;
}          
       
                      
void back(int k)
{ 
  if(k>n) calcul();
  else
  {
      inm[k]=1;back(k+1);
      inm[k]=-1;back(k+1);
  }
}
void read()
{int i,j;
     freopen("flip.in","r",stdin);
     scanf("%d %d",&n,&m);
     for(i=1; i<=n; ++i)
	 for(j=1; j<=m; ++j)
              scanf("%d",& a[i][j]);       
}
int main()
{
    read();
    back(1);
    freopen("flip.out","w",stdout);
    printf("%d",max);
    return 0;
}