#include <cstdio>

#include <fstream>

using namespace std;

int n, m, mx = -1000000;
int sol[18];
int M[18][18];

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

int suma()  {
    int ax, rez = 0;
    for (int i = 1 ; i <= n ; i++)    {
        ax = 0;
        for (int j = 1 ; j <= m ; j++)
            ax += sol[j] ? (- M[i][j]) : M[i][j];
        if (ax < 0)
            ax = -ax;
        rez += ax;
    }
    return rez;
}

void back (int k)   {
    int x;
    if (k == m + 1)
        x = suma(), mx = x > mx ? x : mx;
    else  {
        for (int i = 0 ; i < 2 ; i++)   {
            sol[k] = i;
            back(k + 1);
        }
    }
}

int main()  {
    fin >> n >> m;
    for (int i = 0 ; i < n ; i++)
        for (int j = 0 ; j < m ; j++)
            fin >> M[i + 1][j + 1];
    back(1);
    fout << mx;
    return 0;
}