#include <fstream>

using namespace std;

ifstream f("flip.in");
ofstream g("flip.out");

int n, m, a[16][16], maxi, s[16];

void sum() {

    int s1, s2 = 0;
    for (int i = 1; i <= n; ++i) {

        s1 = 0;
        for (int j = 1; j <= m; ++j)
            s1 += s[j] * a[i][j];
        if (s1 < 0)
            s2 -= s1;
        else
            s2 += s1;
    }
    if (s2 > maxi)
        maxi = s2;
}

void bkt (int k) {

    if (k > m)
        sum();
    else
        for (int l = -1; l <= 1; ++l)
            if (l != 0) {

                s[k] = l;
                bkt (k + 1);
            }
}

int main() {

    f >> n >> m;
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= m; ++j)
            f >> a[i][j];
    bkt (1);
    g << maxi;
}