#include <iostream>
#include <fstream>

using namespace std;

int v[17][17], n, m, MAX, c[17];

void vezi(){
	int i, sum=0;

	for (i = 1; i <= m; ++i){
		if (c[i] < 0)
			sum += c[i] * (-1);
		else
			sum += c[i];
	}

	if (MAX < sum) MAX = sum;
}

void back(int k) {
	if (k>n) {
		vezi();
		return;
	}

	for (int i = 1; i <= m; ++i)
		c[i] += v[k][i]*2*(-1);
	back(k + 1);

	for (int i = 1; i <= m; ++i)
		c[i] += v[k][i]*2;
	back(k + 1);
}



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

	int i, j;

	f >> n >> m;
	for (i = 1; i <= n; ++i)
		for (j = 1; j <= m; ++j){
			f >> v[i][j];
			c[j] += v[i][j];
		}
	//memset(s, 1, sizeof(s));

	back(1);

	g << MAX;

	f.close();
	g.close();
	return 0;
}