#include <bits/stdc++.h>

#define NN 1 << 4
#define oo 0x3f3f3f
using namespace std;

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

int n, m, s[NN + 1], a[NN + 1][NN + 1];

void Read()
{
    fin >> n >> m;
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            fin >> a[i][j], s[j] += a[i][j];
}

inline int sum()
{
    int answ = 0;
    for (int j = 0; j < m; ++j)
        answ += (s[j] > 0 ? s[j] : -s[j]);
    return answ;
}

int Solve()
{
    int answ = -oo;
    for (int mask = 0; mask < (1 << n); mask++)
	{
		for (int i = 0; (1 << i) <= mask; i++)
			if (mask & (1 << i))
            {
                for (int j = 0; j < m; ++j)
                    s[j] -= (a[i][j] << 1);
            }

        answ = max(answ, sum());

        for (int i = 0; (1 << i) <= mask; i++)
			if (mask & (1 << i))
            {
                for (int j = 0; j < m; ++j)
                    s[j] += (a[i][j] << 1);
            }
	}
	return answ;
}

int main()
{
    Read();
    fout << Solve();
    return 0;
}