#include <iostream>
#include <fstream>
using namespace std;
ifstream f ("flip.in");
ofstream g ("flip.out");
int n,m,a[17][17],i,j,sl[17],sc[17],s,ss;
int main()
{
    f >> n >> m;
    for(i=1; i<=n; i++) {
        for(j=1; j<=m; j++) {
            f >> a[i][j];
            sl[i]+=a[i][j];
            sc[j]+=a[i][j];
            s=s+a[i][j];
        }
    }
    for(i=1; i<=n; i++) {
        ss=0;
        for(j=1; j<=m; j++) {
            ss=ss+(a[i][j]*-1);
        }
        if(ss>sl[i]) {
            for(j=1; j<=m; j++) {
                s=s-a[i][j];
                sl[i]=sl[i]-a[i][j];
                sc[j]=sc[j]-a[i][j];
                a[i][j]=a[i][j]*-1;
                s=s+a[i][j];
                sl[i]=sl[i]+a[i][j];
                sc[j]=sc[j]+a[i][j];
            }
        }
    }
    for(j=1; j<=m; j++) {
        ss=0;
        for(i=1; i<=n; i++) {
            ss=ss+(a[i][j]*-1);
        }
        if(ss>sc[j]) {
            for(i=1; i<=n; i++) {
                s=s-a[i][j];
                sl[i]=sl[i]-a[i][j];
                sc[j]=sc[j]-a[i][j];
                a[i][j]=a[i][j]*-1;
                s=s+a[i][j];
                sl[i]=sl[i]+a[i][j];
                sc[j]=sc[j]+a[i][j];
            }
        }
    }
    g << s;
    return 0;
}