#include <iostream>
#include <fstream>

using namespace std;

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

int v[19][19], frecv[19], suma, suma_max, suma_t;

void afisare (int n, int m)
{
    suma_t=0;
    for (int j=1;j<=m;++j)
    {
        suma=0;
        for (int i=1;i<=n;++i)
        {
            if (frecv[i])
                suma-=v[i][j];
            else
                suma+=v[i][j];
        }
        if (suma<0)
            suma_t-=suma;
        else
            suma_t+=suma;
    }
    suma_max=max(suma_t,suma_max);
}

void backtracking (int n, int pas, int m)
{
    if (pas<=n)
    {
        for (int i=0;i<=1;++i)
        {
                frecv[pas]=i;
                backtracking (n, pas+1, m);
        }
    }
    else
        afisare (n, m);
        return;
}

int main()
{
    int n, m;
    fin>>n>>m;
    for (int i=1;i<=n;++i)
        for (int j=1;j<=m;++j)
            fin>>v[i][j];
    backtracking (n, 1, m);
    fout<<suma_max;
}