#include <fstream>
using namespace std;

ifstream f("flip.in");
ofstream g("flip.out");

 

int n, m, v[17][17], c1[17], smax, s,s2, k, c2[17];

 

int main ()

{

   

    f>>n>>m;

    for(int i=1;i<=n;i++)

        for(int j=1;j<=m;j++)

        {

            f>>v[i][j];

            smax+=v[i][j];

        }

    while(c1[1]==0)

    {

        while(c2[1]==0)

        {

            s=0;

            for(int i=1;i<=n;i++)

            {

                int s2=0;

                for(int j=1;j<=m;j++)// in c2 generam vectorul caracteristic pentru //semnele coloanelor

                    if(c2[j]==0 && c1[i]==0)

                        s2+=a[i][j];

                    else

                        s2-=a[i][j];

                }

                s+=abs(s2);

            }

            smax=max(s, smax);

            for(k=m;c2[k]==1;k--)

                c2[k]=0;

            c2[k]=1;

        }

        for(k=n;c1[k]==1;k--)

            c1[k]=0;

        c1[k]=1;

    }

    g<<smax;

    return 0;


}