#include <fstream>

using namespace std;

ifstream fin ("flip.in");
ofstream fout("flip.out");

int a[19][19],mk[19],m,n,i,j,mx,nr,k,s,ss;

int main()
{
    fin >> n >> m;

    mx=-1000000;

    for (i=1;i<=n;++i)
    {
        for (j=1;j<=m;++j)
        {
            fin >> a[i][j];
        }
    }

    nr=(1<<n)-1;

    for (k=1;k<=nr;++k)
    {
        for (i=1;i<=n;++i)
        {
            if ( k>>(i-1)&1 )
            {
                mk[i]=k;
            }


        }

        ss=0;

        for (j=1;j<=m;++j)
        {
            s=0;
            for (i=1;i<=n;++i)
            {
                if (mk[i]==k)
                {
                    s+=-a[i][j];
                }
                else s+=a[i][j];

            }

            if (s<0) s=-s;

            ss+=s;

        }

        if (ss>mx) mx=ss;
    }

    fout << mx;

    return 0;
}