#include <fstream>

using namespace std;

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

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


void fooBar() {
    for (int j = 1; j <= M; j++) {
        firstSum = 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 <= M) {
        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;
}