#include <iostream>
#include <fstream>
#include <climits>
using namespace std;
ifstream fin ("flip.in");
ofstream fout ("flip.out");
int M[17][17],n,m,v[17],sol=INT_MIN;
void citire()
{
    fin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
        fin>>M[i][j];
    v[1]=1;
}
int suma()
{  int S=0;
    for(int i=1;i<=n;i++)
    {
        int s=0;
        for(int j=1;j<=m;j++)
        {
            s+=v[j]*M[i][j];
        }
        S+=max(s,-s);

    }
    return S;
}
void rezolvare(int x)
{
    if(x==m+1)
    {
        sol=max(sol,suma());
        return;
    }
    v[x]=1;
    rezolvare(x+1);
    v[x]=-1;
    rezolvare(x+1);

}
int main()
{
    citire();
    rezolvare(1);
       fout<<sol;
    return 0;
}