#include <iostream>

using namespace std;

int main()
{
	freopen("flip.in", "r", stdin);
	freopen("flip.out", "w", stdout);

	int m, n;
	cin >> m >> n;

	int a[16][16];
	int max = -INT_MAX;

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

	for (int c = 0; c < (1 << n); c++)
	{
		int csum = 0;
		for (int i = 0; i < m; i++)
		{
			int lsum = 0;
			for (int j = 0; j < n; j++)
				lsum += ( (c & (1<< i)) ? 1 : -1 ) * a[i][j];
			if (lsum < 0)
				lsum = -lsum;
			csum += lsum;
		}

		if (csum > max)
			max = csum;
	}

	cout << max;
}