#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n,m,MAX,x[20][20],stiva[20];
void backtrack(int niv)
{
    int i,j,k,suma,linie;
    for (k=1;k<=2;k++)
    {
        stiva[niv]=k;
        if (niv==m)
        {
            suma=0;
            for (i=1;i<=n;i++)
            {
                linie=0;
                for (j=1;j<=m;j++)
                {
                    if (stiva[j]==1)
                        linie+=x[i][j];
                    else
                        linie-=x[i][j];
                }
                if (linie<0)
                    suma-=linie;
                else suma+=linie;
            }
            MAX=max(MAX,suma);
        }
        else backtrack(niv+1);
    }
}
int main()
{
    fin>>n>>m;
    int i,j;
    for (i=1;i<=n;i++)
    {
        for (j=1;j<=m;j++)
        {
            fin>>x[i][j];
            MAX+=x[i][j];
        }
    }
    backtrack(1);
    fout<<MAX;
    /// TEMA problema numere8 cu backrtacking, flip, reteta https://www.infoarena.ro/problema/reteta
    /// Subiect admitere 2018 vara UBB
    return 0;
}