#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n;
  cin >> n;
  int aux, sum = 0;
  int comptNeg = 0, compt0 = 0;
  int mini = -2000;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> aux;
    if (aux < 0) {
      sum = sum - aux;
      comptNeg++;
      if (aux > mini) {
        mini = aux;
      }
    } else if (aux == 0) {
      compt0++;
    } else {
      sum = sum + aux;
      if (-aux > mini) {
        mini = -aux;
      }
    }
  }
  if (n % 2 == 0 && compt0 == 0 && comptNeg % 2 == 1) {
    cout << sum + 2 * mini << endl;
  } else {
    cout << sum << endl;
  }
}
