#include <fstream>

#define DIM 17

using namespace std;

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

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

int main()
{
    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;
}