#include <fstream>
using namespace std;

const int NMAX=16,MMAX=16;
int tabla_joc[1+NMAX][1+MMAX];
int n,m,i,j;
int semn[1+NMAX];
int sumCrt,sumC;
int sumMax = -NMAX*NMAX*1000000;

void generare(int index)
{
    if(index>n)
    {
        sumCrt=0;
        for(j=1;j<=m;j++)
        {
            sumC=0;
            for(i=1;i<=n;i++)
            {
                sumC=sumC+tabla_joc[i][j]*semn[i];
            }
            if(sumC>0)
            {
                sumCrt=sumCrt+sumC;
            }
            else
            {
                sumCrt=sumCrt-sumC;
            }
        }
        if(sumCrt>sumMax)
        {
            sumMax=sumCrt;
        }
    }
    else
    {
        semn[index]=1;
        generare(index+1);
        semn[index]=-1;
        generare(index+1);
    }
}

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

    f>>n>>m;
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            f>>tabla_joc[i][j];
        }
    }

    generare(1);

    g<<sumMax;

    return 0;
}