#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");

const int NMAX = 16 + 5;
const int INF = 0x3f3f3f3f;

int n, m, maxim = -INF;
int semn_linie[NMAX];
int v[NMAX][NMAX];

void columns()
{
    int sum = 0;

    for (int j = 1; j <= m; ++j)
    {
        int curr = 0;

        for (int i = 1; i <= n; ++i)
            curr += v[i][j] * semn_linie[i];

        sum += abs(curr);
    }

    maxim = max(maxim, sum);
}

void backtr_line(int poz)
{
    if (poz == n)
    {
        columns();
        return;
    }

    backtr_line(poz + 1);

    semn_linie[poz] = -1;
    backtr_line(poz + 1);
    semn_linie[poz] = 1;
}

void write()
{
    fout << maxim;
}

void read()
{
    fin >> n >> m;
    for (int i = 1; i <= n; ++i)
    {
        semn_linie[i] = 1;
        for (int j = 1; j <= m; ++j)
            fin >> v[i][j];
    }
}

int main()
{
    read();
    backtr_line(1);
    write();

    return 0;
}