#include <fstream>

using namespace std;

int main()
{
    int a[50][50], n, m, i,j, s, s1, s2;
    ifstream f ("flip.in");
    ofstream g ("flip.out");
    f>>n>>m;
    for (i=1; i<=n; i++)
    for (j=1; j<=m; j++) f>>a[i][j];
    s=0;
    for (i=1; i<=n; i++)
    {
        s1=0; s2=0;
        for (j=1; j<=m; j++)
        {
            s1=s1+a[i][j];
            s2=s2-a[i][j];
        }
        if (s2>s1)
        {
            for (j=1; j<=m; j++) a[i][j]=-a[i][j];
            s=s+s2;
        }
        else s=s+s1;
    }
    for (j=1; j<=m; j++)
    {
        s1=0;
        for (i=1; i<=n; i++) s1=s1-a[i][j];
        if (s+2*s1>s) s=s+2*s1;
    }
    g<<s;
    f.close();
    g.close();
    return 0;
}