#include <fstream>

using namespace std;

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

int arr[17][17], vec[17], MAX = 0, N, M, i, j;


void fooBar() {
    int firstSum = 0, secondSum, i, j;

    for (i = 1; i <= M; i++) {
        secondSum = 0;

        for (j = 1; j <= N; j++) {
            secondSum += vec[j] * arr[j][i];

            if (secondSum < 0)
                secondSum = -secondSum;

            firstSum += secondSum;
        }

        if (MAX < firstSum)
            MAX = firstSum;
    }
}

void backTrack(int k) {
    if (k > N)
        fooBar();

    else {
        vec[k] = 1;
        backTrack(k + 1);
        vec[k] = -1;
        backTrack(k + 1);
    }
}

int main() {
    fin >> N >> M;

    for (i = 1; i <= N; i++)
        for (j = 1; j <= M; j++) {
            fin >> arr[i][j];
        }

    backTrack(1);

    fout << MAX;
}