#include <fstream>

using namespace std;

ifstream cin("flip.in");
ofstream cout("flip.out");

    int n, m, a[20][20], v[20], ans;

    void bac(int k) {

        if (k <= n) {

            v[k] = 1;
            bac(k + 1);
            v[k] = -1;
            bac(k + 1);

        }

        else {

                int f_sum = 0;

            for (int j = 1; j <= m; ++j) {
                int sum = 0;
                for (int i = 1; i <= n; ++i)
                    sum += a[i][j] * v[i];

                if (sum < 0)
                    sum *= -1;
                f_sum += sum;
            }
            ans = max(ans, f_sum);
        }

   }

int main()
{
    cin >> n >> m;

    for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= m; ++j) {

        cin >> a[i][j];
        ans += a[i][j];
    }

    bac(1);
    cout << ans;
    return 0;
}