#include <cstdio>
#include <algorithm>
using namespace std;
int n,m,i,j,sumaMAX(0);
int M[17][17],Aux[17];
void openIOFiles()
{
 freopen("flip.in","r",stdin);
 freopen("flip.out","w",stdout);
}

void verificare()
{
 int i,j,s(0),sPart(0);
 for(j=1;j<=m;++j){
                   s=0;
                   for(i=1;i<=n;++i) s+=M[i][j]*Aux[i];
                   if (s<0) s*=-1;
                   sPart+=s;
                   }
 sumaMAX=max(sumaMAX,sPart);
}

void flip(int k)
{
 if(k>n) verificare();
    else{
        Aux[k]=-1;
        flip(k+1);
        Aux[k]=1;
        flip(k+1);
        }
}

int main()
{
 openIOFiles();
 scanf("%d%d",&n,&m);
 for (i=1;i<=n;++i)
    for (j=1;j<=m;++j) scanf("%d",&M[i][j]), sumaMAX+=M[i][j];
 flip(1); 
 printf("%d",sumaMAX);   
return 0;
}