#include <fstream.h>

ifstream f1("flip.in");
ofstream f2("flip.out");

int main ()
{
    long n,m,a[18][18],i,j,s1,s2,s;
    f1>>n;
    f1>>m;
    for (i=1;i<=n;i++){
        for (j=1;j<=m;j++){
            f1>>a[i][j];
        }
    }
    for (i=1;i<=n;i++){
        s1=0;
        for (j=1;j<=m;j++){
            s1=s1+a[i][j];
        }
        s2=0;
        for (j=1;j<=m;j++){
            s2=s2-a[i][j];
        }
        if (s2>s1)for (j=1;j<=m;j++)a[i][j]=-a[i][j];
    }
    for (j=1;j<=m;j++){
        s1=0;
        for (i=1;i<=n;i++){
            s1=s1+a[i][j];
        }
        s2=0;
        for (i=1;i<=n;i++){
            s2=s2-a[i][j];
        }
        if (s2>s1)for (i=1;i<=n;i++)a[i][j]=-a[i][j];
    }
    s=0;
    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            s=s+a[i][j];
    f2<<s<<'\n';
    
f1.close();
f2.close();
return 0;
}