#include<iostream>
#include<fstream>
#include<algorithm>

using namespace std;

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

int s,scol,a[100][100],N,M;
int st[100];

int suma=-9999999;

void Citire()
{
  int i,j;
  fin>>M>>N;
  for (i=1;i<=M;i++)
    for (j=1;j<=N;j++)
        fin>>a[i][j];
}

void Afisare()
{
    int i,j;
    scol=0;
    for (i=1;i<=N;i++)
    {
        s=0;
        for (j=1;j<=M;j++)
        {
            if (st[j]==1) s=s+a[j][i]*(-1);
            else          s+=a[j][i];
        }
        if (-s>s) scol+=-s;
        else      scol+=s;
    }

    suma=max(suma,scol);
}
void Back(int top)
{
    int i;
    if (top==M+1) Afisare();
    else for (i=0;i<=1;i++)
    {
        st[top]=i;
        Back(top+1);
    }
}

int main ()
{
    Citire();
    Back(1);
    fout<<suma<<"\n";
    fin.close();
    fout.close();
    return 0;
}