#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
long  long n,m,i,j,c,s,suma,sol,v[20][20];
int main()
{
   fin>>n>>m;
   for(i=1;i<=n;i++)
    for(j=1;j<=m;j++)
    fin>>v[i][j];
    int y=(1<<m);
   for(c=0;c<=y-1;c++){
        suma=0;
        for(i=1;i<=n;i++){
                s=0;
            for(j=1;j<=m;j++)
            {
                if(  (  (c>>(j-1))  &1)==1 )
                s+=v[i][j];
            else
                s-=v[i][j];
            }

        if(s<0)
            suma-=s;
        else
            suma+=s;
        }
    sol=max(suma,sol);


   }
   fout<<sol;
}