#include <algorithm>
#include <fstream>

using namespace std;

int a[20][20];

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

	int n, m, ans = 0;
	f >> n >> m;

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

	int lim = 1 << n;
	for (int i = 0; i < lim; i++) {
		int pans = 0;
		for (int k = 0; k < m; k++) {
			int s1 = 0, s2 = 0;
			for (int j = 0; j < n; j++)
				if ((1<<j) & i) {
					s1 -= a[j][k];
					s2 += a[j][k];
				}
				else {
					s1 += a[j][k];
					s2 -= a[j][k];
				}

				pans += max(s1, s2);
		}

		ans = max (ans, pans);
	}

	g << ans;

	return 0;

}