#include <fstream>

using namespace std;

int flip[17][17];
int cflip[17][17];
int maxim = -256000000;
int main()
{
    ifstream fin("flip.in");
    ofstream fout("flip.out");

    int n, m;

    fin >> n >> m;

    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
        {
            fin >> flip[i][j];
        }

    for(int bit = 0; bit < (1 << n); bit++)
    {
        int sumt = 0;
        for(int i = 0; i < n; i++)
            for(int j = 0; j < m; j++)
                if(bit & (1 << i))
                    cflip[i][j] = -flip[i][j];
                else
                    cflip[i][j] = flip[i][j];

        for(int j = 0; j < m; j++)
        {
            int sumc = 0;
            for(int i = 0; i < n; i++)
                sumc += cflip[i][j];
            if(sumc < 0)
                sumc = -sumc;
            sumt += sumc;
        }
        if(sumt > maxim)
            maxim = sumt;
    }

    fout << maxim;

    return 0;
}