#include <iostream>
#include <fstream>
#include <cstdio>

using namespace std;

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

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

	for (i = 1; i <= m; ++i){
		sum = 0;
		for (j = 1; j <= n; ++j)
			sum += (s[j] * v[j][i]);
		if (sum < 0) sum *= (-1);
		t += sum;
	}

	if (MAX < t) MAX = t;
}

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

	s[k] = -1;
	back(k + 1);
	s[k] = 1;
	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];
	//memset(s, 1, sizeof(s));

	back(1);

	g << MAX;

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