#include <cstdio>
#include <algorithm>

using namespace std;

int v[32][32], n, m, ma;

int aabs (int x)
{
    return max (x, -x);
}

inline void sub (int x)
{
    int cv[32][32];
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= m; ++j)
            cv[i][j] = v[i][j];

    for (int i = 1; i <= n && x; ++i)
    {
        if (x & 1)
            for (int j = 1; j <= m; ++j)
                cv[i][j] *= -1;

        x >>= 1;
    }

    int rez = 0;
    for (int j = 1; j <= m; ++j)
    {
        int sum = 0;
        for (int i = 1; i <= n; ++i)
            sum += cv[i][j];

        rez += aabs (sum);
    }

    ma = max (ma, rez);
}

int main ()
{
    freopen ("flip.in", "r", stdin);
    freopen ("flip.out", "w", stdout);

    scanf ("%d %d", &n, &m);

    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= m; ++j)
            scanf ("%d", &v[i][j]);

    for (int i = 1; i < (1 << n); ++i)
        sub (i);

    printf ("%d\n", ma);

    return 0;
}