#include<fstream>
using namespace std;
int a[20][20],i,m,n,s;
ifstream fin("flip.in");
ofstream fout("flip.out");
int main() {
    long i,j,s1,r,t;
    fin>>n;
    fin>>m;
    for (i=0; i<n; i++)
        for (j=0; j<m; j++)fin>>a[i][j];
    for (r=0; r<(1<<m); r++) {
        s1=0;
        for (i=0; i<n; i++) {
            for (t=j=0; j<m; j++)
                if (r&(1<<j))t+=-a[i][j];
                else t+=a[i][j];
            if (t>-t)s1+=t;
            else s1+=-t;
        }
        if (s1>s)s=s1;
    }
    fout<<s;
    return 0;
}