#include <cstdio>
#include <vector>

using namespace std;

int n, m;
int mat[20][20];
int sumeLinie[20];
int sumeColoane[20];
vector<int> sol;
int solx[20];
int maxSuma = 0;
int sumaInitiala;

void citire()
{
    scanf("%d %d", &n, &m);

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < m; j++)
        {
            scanf("%d", &mat[i][j]);
            sumeLinie[i] += mat[i][j];
            sumeColoane[j] += mat[i][j];
            maxSuma += mat[i][j];
            sumaInitiala += mat[i][j];
        }
    }
}

void calculareSuma()
{
    int suma = sumaInitiala;

    for(int i = 0; i < 20; i++)
    {
        solx[i] = 0;
    }

    for(int i = 0; i < sol.size(); i++)
    {
        suma -= 2 * sumeLinie[sol[i]];
        solx[sol[i]] = 1;
    }

    int tmp1;

    for(int i = 0; i < m; i++)
    {
        tmp1 = 0;

        for(int j = 0; j < n; j++)
        {
            if(solx[j] == 0)
            {
                tmp1 += mat[j][i];
            }
            else
            {
                tmp1 -= mat[j][i];
            }
        }

        if(tmp1 < 0)
        {
            suma += 2 * (-tmp1);
        }
    }

    if(suma > maxSuma)
    {
        maxSuma = suma;
    }
}

void backtracking()
{
    long long limita = (long long)1 << (m);

    for(long long k = 1; k < limita; k++)
    {
        sol.clear();

        for(int i = 0; i <= 16; i++)
        {
            if((k & (1 << i)) != 0)
            {
                sol.push_back(i);
            }
        }

        calculareSuma();
    }

    printf("%d", maxSuma);
}

int main()
{
    freopen("flip.in", "r", stdin);
    freopen("flip.out", "w", stdout);

    citire();
    backtracking();

    return 0;
}