#include <bits/stdc++.h>
using namespace std;
const int MAXN = 110;
const int oo = 1000 * 1000 * 1000;
int n, x, Minus, sum, minimum = oo;
int main() {
  ios_base::sync_with_stdio(false);
  cin >> n;
  for (int i = 0; i < 2 * n - 1; ++i) {
    cin >> x;
    sum += abs(x);
    minimum = min(minimum, abs(x));
    if (x < 0) Minus++;
  }
  if (n % 2 || Minus % 2 == 0)
    cout << sum << endl;
  else
    cout << sum - 2 * minimum << endl;
  return 0;
}
