#include <fstream>
#include <algorithm>

using namespace std;

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

int i, j, N, M, maxim, sum, rez;
int v[20][20];
int a[20];

void bkt(int poz){
    if (poz > M){
        maxim = 0;
        for (i = 1; i <= N; i++){
            sum = 0;
            for (j = 1; j <= M; j++)
                sum += v[i][j] * a[j];
            maxim += abs(sum);
        }
        rez = max(rez, maxim);
    }
    while (poz <= M){
        a[poz] = 1;
        bkt(poz + 1);
        a[poz] = -1;
        bkt(poz + 1);
        poz++;
    }
}

int main(){
    f >> N >> M;
    for (i = 1; i <= N; i++){
        for (j = 1; j <= M; j++)
            f >> v[i][j];
    }
    bkt(0);
    g << rez;

    return 0;
}