#include <fstream>

using namespace std;

ifstream fi("flip.in");
ofstream fo("flip.out");
int rez;
int n,m;
int A[20][20],B[20][20];
int S[20];
int SC[20];
void g(int k)
{
    int i,suma;
    if (k==n)
    {
        for (int i=1;i<=n;i++)
            for (int j=1;j<=m;j++)
                if (S[i]==0)
                    B[i][j]=A[i][j];
                else
                    B[i][j]=-A[i][j];
        for (int i=1;i<=m;i++)
            SC[i]=0;
        for (int i=1;i<=n;i++)
            for (int j=1;j<=m;j++)
                SC[j]+=B[i][j];
        suma=0;
        for (i=1;i<=m;i++)
            if (SC[i]>=0)
                suma=suma+SC[i];
            else
                suma=suma-SC[i];
        if (suma>rez)
            rez=suma;
    }
    else
        for (i=0;i<=1;i++)
        {
            S[k+1]=i;
            g(k+1);
        }
}

int main()
{
    fi>>n>>m;
    for (int i=1;i<=n;i++)
        for (int j=1;j<=m;j++)
            fi>>A[i][j];
    rez=-1;
    g(0);
    fo<<rez;
    fi.close();
    fo.close();
    return 0;
}