#include <iostream>
#include <cmath>
using namespace std;
int n;
int sum = 0;
int main () {
	cin >> n;
	int minn = 1e+9;
	int k = 0;
	for (int i = 0; i <= (2 * (n - 1)); i++) {
		int t;
		cin >> t;
		if (t < 0)
			k++;
		sum += abs(t);
		minn = min (minn, abs(t));
	}
	if (k >= n ) {
		k -= n;
	}
	if (!(k % 2)) {
		cout << sum;
	} else {
		cout << sum - 2 * minn;
	}
	return 0;
}