#include <fstream>
#define DIM 18


using namespace std;
int a[DIM][DIM], v[DIM];
int n, m, i, j, s, sum ,maxim;

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

    fin>>n>>m;

    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            fin>>a[i][j];

    while (v[1] == 0) {
        j = m;
        while (v[j] == 1) {
            v[j] = 0;
            j -- ;
        }
        v[j] = 1;

        sum = 0;
        for (i=1;i<=n;i++) {
            s = 0;
            for (j=1;j<=m;j++)
                if (v[j] == 0)
                    s += a[i][j];
                else
                    s -= a[i][j];
            if (s > 0)
                sum += s;
            else
                sum -= s;

        }

        if (sum > maxim)
            maxim = sum;

    }

    fout<<maxim<<"\n";

    return 0;
}