#include <fstream>

using namespace std;

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

int n, m, i, j;
int a[18][18];
int smax;
int v[18];
bool u[18];

void verif()
{
    int s = 0, aux = 0;
    for (int j = 1; j <= m; j++) {
        aux = 0;
        for (int i = 1; i <= n; i++)
            if (!u[i])
                aux += a[i][j];
            else
                aux -= a[i][j];

        if(aux < 0)
            aux = -aux;

        s += aux;
    }
    smax = max(smax, s);
}

void bkt(int k)
{
    for (int i = v[k - 1] + 1; i <= n; i++) {
        v[k] = i;
        u[i] = 1;
        verif();
        if (k < n)
            bkt(k + 1);
        u[i] = 0;
    }
}

int main()
{
    f >> n >> m;
    for (i = 1; i <= n; i++)
        for (j = 1; j <= m; j++) {
            f >> a[i][j];
            smax += a[i][j];
        }
    bkt(1);
    g << smax;
    return 0;
}