#include <fstream>
using namespace std;

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

    int n, m;
    fin >> n >> m;

    int a[20][20];

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

    long long maxim = -1e18;


    for(int mask = 0; mask < (1 << n); mask++) {

        long long sumaTotala = 0;


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

            long long sumaCol = 0;

            for(int i = 0; i < n; i++) {

                int val = a[i][j];


                if(mask & (1 << i))
                    val = -val;

                sumaCol += val;
            }


            if(sumaCol < 0)
                sumaCol = -sumaCol;

            sumaTotala += sumaCol;
        }

        if(sumaTotala > maxim)
            maxim = sumaTotala;
    }

    fout << maxim;

    return 0;
}