#include <fstream>

using namespace std;

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

int a[17][17], s[17], ans, n, m;

void back(int k)
{
	if (k == n+1)
	{
		int tempans = 0;
		for (int i = 1; i <= m; ++i)
			tempans += s[i] > 0 ? s[i] : -s[i];
		ans = max(ans, tempans);
		return;
	}

	back(k+1);

	for (int i = 1; i <= m; ++i)
	{
		s[i] -= 2*a[k][i];
	}

	back(k+1);

	for (int i = 1; i <= m; ++i)
	{
		s[i] += 2*a[k][i];
	}
}

int main()
{
    fin >> n >> m;

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

	fout << ans;
}