#include <fstream>
using namespace std;

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

int n, m, a[20][20], max_sum, s[20];

void calc()
{
    int total = 0;
    for (int i = 1; i <= n; ++i)
    {
        int lin = 0;
        for (int j = 1; j <= m; ++j)
            lin -= s[j] * a[i][j]; 
        if (lin < 0)
            total -= lin;
        else
            total += lin;
    }
    if (total > max_sum)
        max_sum = total;
}

void back(int k)
{
    if (k > m)
        calc();
    else
    {
        s[k] = -1;
        back(k + 1);
        s[k] = 1;
        back(k + 1);
    }
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= m; ++j)
            fin >> a[i][j];
    back(1);
    fout << max_sum;

    fin.close();
    fout.close();

    return 0;
}