#include <fstream>

using namespace std;

int m, n, i, j, conf, sol, s, maxSol, a[20][20];
int main()
{
    ifstream fi("flip.in");
    ofstream fo("flip.out");
    fi >> m >> n;
    for(i = 0; i < m; i++)
        for(j = 0; j < n; j++)
            fi >> a[i][j];
    int maxConf = (1<<m);
    for(conf = 0; conf < maxConf; conf++)
    {
        sol = 0;
        for(j = 0; j < n; j++)
        {
            s = 0;
            for(i = 0; i < m; i++)
                s += (((1<<i)&conf)>0) ? (-a[i][j]) : a[i][j];
            sol += (s > 0) ? s : (-s);
        }
        if(sol > maxSol) maxSol = sol;
    }
    fo << maxSol << "\n";
    return 0;
}