#include <fstream>
using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");

#define MAXN 20

int n, m, rez, v[MAXN][MAXN];

inline void flip(int l) {
    for (int i = 1; i <= m; ++i)
        v[l][i] *= -1;
}

int abs(int a) {
    if (a < 0)
        return -a;
    return a;
}

void sol() {
    int i, j, sumCol, sumTot = 0;
    for (i = 1; i <= m; ++i) {
        sumCol = 0;
        for (j = 1; j <= n; ++j)
            sumCol += v[j][i];
        sumTot += abs(sumCol);
    }
    rez = max(rez, sumTot);
}

void back(int l) {
    if (l > n) {
        sol();
        return;
    }
    back(l + 1);
    flip(l);
    back(l + 1);
    flip(l);
}

int main() {
    int i, j;
    fin >> n >> m;
    for (i = 1; i <= n; ++i)
        for (j = 1; j <= m; ++j)
                fin >> v[i][j];
    back(1);
    fout << rez << "\n";
    return 0;

}