#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, p = 0, sum = 0, mn = 1111;
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    int a;
    cin >> a;
    if (0 <= a) p++;
    sum += abs(a);
    mn = min(abs(a), mn);
  }
  cout << ((n % 2 == 0 && p % 2 == 0) ? sum - 2 * mn : sum) << endl;
  return 0;
}
