#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  vector<int> nos(2 * N - 1), absVals(2 * N - 1);
  int total = 0, minuses = 0;
  for (int i = 0; i < nos.size(); i++)
    cin >> nos[i], total += abs(nos[i]), absVals[i] = abs(nos[i]),
                                         minuses += (nos[i] < 0) ? 1 : 0;
  sort(nos.begin(), nos.end());
  sort(absVals.begin(), absVals.end());
  if (nos[0] >= 0 || N % 2 == 1 || minuses % 2 == 0)
    cout << total << endl;
  else if (nos[0] < 0) {
    total -= 2 * absVals[0];
    cout << total << endl;
  }
  return 0;
}
