#include <fstream>

using namespace std;

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

int arr[100][100], vec[100], firstSum = 0, secondSum, MAX = 0, N, M;


void fooBar() {
    for (int j = 1; j <= M; j++) {
        secondSum = 0;

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

            if (secondSum < 0)
                secondSum = -secondSum;

            firstSum += secondSum;
        }

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

void backTrack(int k) {
    if (k <= N) {
        vec[k] = 1;
        backTrack(k + 1);
        vec[k] = -1;
        backTrack(k + 1);
    }

    else
        fooBar();
}

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

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

    backTrack(1);

    fout << MAX;
}