#include <fstream>
using namespace std;

int a[17][17], s[17], i, j, k, n, m, sc, smod, maxi, nr;

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

int main() {
    f>>n>>m;
    for (i=1; i<=n; ++i)
        for (j=1; j<=m; ++j)
            f>>a[i][j];
    nr=1<<n;
    for (i=0; i<nr; ++i) {
        for (j=0; j<n; ++j)
            if (i&(1<<j))
                s[j+1]=-1;
            else
                s[j+1]=1;
        smod=0;
        for (j=1; j<=m; ++j) {
            sc=0;
            for (k=1; k<=n; ++k)
                sc+=a[k][j]*s[k];
            if (sc<0)
                smod-=sc;
            else
                smod+=sc;
        }
        if (smod>maxi)
            maxi=smod;
    }
    g<<maxi;
    return 0;
}