#include <fstream>

using namespace std;

int n,st[20],m,b[20][20],c[20][20],smax;

inline void Citire()
{
    int i,j;
    ifstream fin("flip.in");
    fin>>n>>m;
    for(i=1;i<=n;++i)
        for(j=1;j<=m;++j)
            fin>>b[i][j];
    fin.close();
}

inline void Actualizare()
{
    int i,j,suma,s;
    for(j=1;j<=m;++j)
    {
        if(st[j]==0)
            for(i=1;i<=n;++i)
                c[i][j]=b[i][j];
        else
            for(i=1;i<=n;++i)
                c[i][j]=-b[i][j];
    }
    suma=0;
    for(i=1;i<=n;++i)
    {
        s=0;
        for(j=1;j<=m;++j)
            s+=c[i][j];
        if(s<0)
            suma-=s;
        else
            suma+=s;
    }
    smax=max(smax,suma);
}

inline void Back(int k)
{
    int i;
    if(k==m+1)  Actualizare();
    else
        for(i=0;i<=1;++i)
        {
            st[k]=i;
            Back(k+1);
        }
}

inline void Afisare()
{
    ofstream fout("flip.out");
    fout<<smax<<"\n";
    fout.close();
}

int main()
{
    Citire();
    Back(1);
    Afisare();
    return 0;
}