#include <fstream>
int n, m, i, S_max = -256000001, S1, S2, S, j, k, mat[16][16];
int main() {
    std :: ios_base :: sync_with_stdio(0);
    std :: ifstream fin("flip.in");
    fin >> n >> m;
    for (i = 0; i != n; ++ i)
        for (j = 0; j != m; ++ j)
            fin >> mat[i][j];
    fin.close();
    for (i = 0; i != (1 << (n + 1)); ++ i) {
        S = 0;
        for (k = 0; k != m; ++ k) {
            S1 = S2 = 0;
            for (j = 0; j != n; ++ j) {
                if ((i & (1 << j))) {
                    S1 -= mat[j][k];
                    S2 += mat[j][k];
                }
                else {
                    S1 += mat[j][k];
                    S2 -= mat[j][k];
                }
            }
            S += std :: max(S1, S2);
        }
        S_max = std :: max(S, S_max);
    }
    std :: ofstream fout("flip.out");
    fout << S_max;
    fout.close();
    return 0;
}