#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");

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