#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, fu = 0, result = 0, minz = 100000;
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    int temp;
    cin >> temp;
    if (temp < 0) {
      fu++;
      temp = -temp;
    }
    if (temp < minz) minz = temp;
    result += temp;
  }
  if (n % 2 == 0 && fu % 2) result -= 2 * minz;
  cout << result << endl;
  return 0;
}
