//#include <iostream>
#include <fstream>
using namespace std;
int n,m,a[20][20],i,j,sn[20],sf;

ifstream cin ("flip.in");
ofstream cout ("flip.out");

void backt(int x)
{
    if(x>n)
    {
        int s1=0;
        for(j=1;j<=n;j++)
        {
            int s2=0;
            for(i=1;i<=n;i++)
            {
                s2=s2+a[i][j]*sn[i];
            }
        if(s2<0)
            s2=-s2;
        s1=s1+s2;
        }
        if(s1>sf)
            sf=s1;
    }
    else
    {
        sn[x]=-1;
        backt(x+1);
        sn[x]=1;
        backt(x+1);
    }
}

int main()
{
    cin>>n>>m;
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=m;j++)
        {
            cin>>a[i][j];
        }
    }
    backt(1);
    cout<<sf;
    return 0;
}