#include <iostream>
#include <fstream>

#define ABS(a) ((a < 0) ? -a : a)

using namespace std;

int main()
{
	int s, n, m, a[16][16], b[16][16];
	int s_aux, s_col;

	freopen("flip.in", "r", stdin);
	// freopen("flip.out", "w", stdout);

	cin >> n >> m;

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

	for (int k = 0; k < (1 << 16); k++)
	{
		for (int i = 0; i < n; i++)
		{
			for (int j = 0; j < m; j++)
			{
				b[i][j] = a[i][j];
			}
		}

		for (int i = 0; i < n; i++)
		{
			if ((1 << i) & k)
			{
				for (int j = 0; j < m; j++)
				{
					b[i][j] *= -1;
				}
			}
		}

		s_aux = 0;
        for (int i = 0; i < m; i++)
        {
			s_col = 0;
			for (int j = 0; j < n; j++)
			{
				s_col += b[j][i];
			}

			s_aux += ABS(s_col);
		}

		if (s_aux > s) s = s_aux;
	}

	cout << s;

	return 0;
}