#include <fstream>
#include <cmath>
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+=v[i][j];
                    else
                        s2-=v[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;


}