#include <fstream>
using namespace std;
ifstream f("flip.in");ofstream g("flip.out");
int n, m, a[20][20], maxim, s[20];
void sum(){
    int ss,st=0;
    for (int i=1;i<=n;i++){
        ss=0;
        for (int j=1;j<=m;j++)
            ss+=s[j]*a[i][j];
        if (ss<0)
            st-=ss;
        else
            st+=ss;
    }
    if (st>maxim) maxim=st;
}
void back(int k){
    if (k>m)  sum();
    else
        for (int l=-1;l<=1;l++)
            if (l!=0)
            {
                s[k]=l;
                back(k+1);
            }
}
int main(){
    f>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            f>>a[i][j];
    back(1);
    g<<maxim;
    return 0;
}