#include <fstream>

using namespace std;

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

int main()
{
    int n,m,a[100][100],i,j,s,sm,sg=0;
    fin>>n>>m;
    for (i=0;i<n;i++)
        for (j=0;j<m;j++)
            fin>>a[i][j];
    for (i=0;i<n;i++);
    {
        s=sm=0;
        for (j=0;j<m;j++)
        {
            sm=sm-a[i][j];
            s=s+a[i][j];
        }
        if ( s<sm )
            for ( j=0;j<m;j++ )
                a[i][j]=-a[i][j];
    }
    for ( i=0;i<m;i++)
    {
        s=sm=0;
        for ( j=0;j<n;j++ )
        {
            s=s+a[j][i];
            sm=sm-a[i][j];
        }
        if (s<sm)
        {
            for (j=0;j<n;j++)
                a[j][i]=-a[j][i];
            sg=sg+sm;
        }
        else
            sg=sg+s;

    }
    fout<<sg;
    fin.close();
    fout.close();
    return 0;
}