#include<fstream>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
long a[20][20],m,n,s,i,j,s1,r,t;
int main()
{

    f>>n>>m;
    for (i=0;i<n;i++)
        for (j=0;j<m;j++)
            f>>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;
    }
    g<<s;
    return 0;
}