#include <cstdio>
using namespace std;
int n, m, i, j, a[17][17], S, smax, x[100000], k;
void rezolva ()
{   int S = 0, s, i, j;
    for (i = 1; i <= n; ++i)
        {   s = 0;
            for (j = 1; j <= m; ++j)
                if (x[j]) s -= a[i][j]; else s += a[i][j];
            if (s < 0) S -= s; else S += s;
        }
    if (S > smax) smax = S;
}
void back ()
{   k = 1; x[k] = -1;
    do
    {   while (x[k] < 1)
            {   x[k]++;
                if (k == m) rezolva (); else x[++k] = -1;
            }
        k--;
    } while (k);
}
int main ()
{   freopen ("flip.in", "rt", stdin);
    freopen ("flip.out", "wt", stdout);
    scanf ("%d%d", &n, &m);
    for (i = 1; i <= n; ++i) for (j = 1; j <= m; ++j) scanf ("%d", &a[i][j]);
    back ();
    printf ("%d\n", smax);
    return 0;
}