#include <fstream>

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

int n, m, i, j, s, sfin, a[17][17];
int main()
{
    fin >> n >> m;
    for (i=1; i<=n; i++){
        s = 0;
        for (j=1; j<=m; j++){
            fin >> a[i][j];
            s+=a[i][j];
        }
        a[i][0] = s;
    }
    for (i=1; i<=m; i++){
        s = 0;
        for (j=1; j<=n; j++){
            s+=a[j][i];
        }
        a[0][i] = s;
    }
    for (i=0; i<=n; i++){
        if (a[i][0] < 0)
            for (j=1; j<=m; j++){
                a[i][j] = a[i][j]*(-1);
            }
    }
    for (i=0; i<=m; i++){
        if (a[0][i] < 0)
            for (j=1; j<=n; j++){
                a[j][i] = a[j][i]*(-1);
            }
    }
    for (i=1; i<=n; i++){
        for (j=1; j<=m; j++){
            sfin+=a[i][j];
        }
    }
    fout << sfin;
    return 0;
}