#include <fstream>
using namespace std;
bool fl(int puteri[], unsigned short n, unsigned short flag)
{
    short s = 0;
    for (short i = 0; i < n; i++)
        if (flag & puteri[i]) s++;
    if (s > n/2 + 1) return true;
    else return false;
}
int main()
{
    ifstream ii ("flip.in");
    ofstream oo ("flip.out");
    unsigned short n, m, i, j, flag;
    ii >> n >> m;  int a[n][m];  int puteri[n+1];
    long long sum = 0, s = 0, cl = 0;
    for (puteri[0] = 1, i = 0; i < n; i++, puteri[i] = puteri[i-1]*2)
        for (j = 0; j < m; j++)
            ii >> a[i][j];
    for (flag = 0; flag < puteri[n]; flag++, s = 0)
    {
        if (fl(puteri, n, flag)) continue;
        for (j = 0; j < m; j++, cl = 0)
        {
            for (i = 0; i < n; i++)
                cl += a[i][j] * (flag & (unsigned short)(puteri[i]) ? 1 : -1);
            s += (cl > 0 ? cl : -cl);
        }
        if (s > sum) sum = s;
    }
    oo << sum;
}