#include <fstream>
#include <iostream>

using namespace std;

#define MAXN 18
#define INF (1LL << 50)


int n, m, a[MAXN][MAXN], x[MAXN];
long long SUM[MAXN];
long long maxx = - INF;

inline int negatee (int z)
{
    return - z ;
}

void solve ()
{
    long long S = 0;

   for (int i = 1; i <= n; ++i)
    {
        int c = SUM[i];

        for (int j = 1; j <= m; ++j)
            if (x[j])
                c += 2 * negatee (a[i][j]);

        if (c < - c)
            S += - c;
        else
            S += c;
    }

    if (S > maxx)
        maxx = S;

}

void back (int k)
{
    for (int i = 0; i <= 1; ++i)
    {
        x[k] = i;

        if (k == m)
            solve();
       else
            back (k + 1);
    }
}


int main()
{
    ifstream f("flip.in");
    ofstream g("flip.out");

    f >> n >> m;

 for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= m; ++j)
        {
           f >> a[i][j];
            SUM[i] += a[i][j];
        }
         back (1);

    g<<maxx;

    f.close();
    g.close();

    return 0;
}