#include <fstream>

using namespace std;

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

int n, m, matrice[20][20], sumaLinii[20], sumaTotal, sumaMax, elem, sumaLiniiInitial[20];

int main()
{
    fin>>n>>m;
    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= m; j++)
        {
            fin>>matrice[i][j];
            sumaLiniiInitial[i] += matrice[i][j];
        }
    }
    for(int k = 0; k < (1<<m); k++)
    {
        for(int i = 1; i <= n; i++)
            sumaLinii[i] = sumaLiniiInitial[i];
        sumaTotal = 0;
        int x = k;
        elem = 0;
        while(x)
        {
            elem++;
            if((x & 1) == 1)
            {
                for(int i = 1; i <= n; i++)
                {
                    sumaLinii[i] -= 2 * matrice[i][elem];
                }
            }
            x /= 2;
        }
        for(int i = 1; i <= n; i++)
        {
            if(sumaLinii[i] < 0)
                sumaTotal -= sumaLinii[i];
            else
                sumaTotal += sumaLinii[i];
        }
        if(sumaMax < sumaTotal)
        {
            sumaMax = sumaTotal;
        }
    }
    fout<<sumaMax;
}