#include <fstream>
using namespace std;
ifstream fin ("flip.in");
ofstream fout ("flip.out");
int b[50][50],v[50],s,n,m;
void Comparare ()
{
    int s1,s2,i,j,a;
    s2=0;
    for (i=1;i<=m;++i)
    {
        s1=0;
        for (j=1;j<=n;++j)
        {
            a=b[j][i];
            if (v[j]==1)
                a=a*-1;
            s1=s1+a;
        }
        if (s1<0)
            s1=s1*-1;
        s2=s2+s1;
    }
    if (s2>s)
        s=s2;
}
void Bkt (int k)
{
    if (k<=n)
    {
        for (int i=0;i<=1;++i)
        {
            v[k]=i;
            Bkt (k+1);
        }
    }
    else
    {
        Comparare ();
    }
}
int main()
{
    int i,j;
    fin >>n>>m;
    for (i=1;i<=n;++i)
    {
        for (j=1;j<=m;++j)
            fin >>b
            [i][j];
    }
    Bkt (1);
    fout <<s;
    return 0;
}