#define _CRT_SECURE_NO_WARNINGS
#include <cstdio>


int main()
{
	int n, m, a[20][20];

	freopen("flip.in", "rt", stdin);
	freopen("flip.out", "wt", stdout);

	scanf ("%d%d", &n, &m);

	for (int i = 0; i < n; i++)
		for (int j = 0; j < m; j++)
			scanf ("%d", a[i] + j);

	int sol = 0;
	for (int x = 0; x < 1 << m; x++)
	{
		int suma = 0;
		for (int i = 0; i < n; i++)
		{
			int linie = 0;
			for (int j = 0; j < m; j++)
				if (x & (1 << j))
					linie += a[i][j];
				else
					linie -= a[i][j];

			if (linie > 0)
				suma += linie;
			else
				suma -= linie;
		}

		if (sol < suma)
			sol = suma;
	}

	printf ("%d\n", sol);
	return 0;
}