#include <bits/stdc++.h>
using namespace std;
int n, a[111111], mi = 1e9, s = 0, k = 0;
int main() {
  cin >> n;
  for (int i = 0; i < n + n - 1; i++)
    cin >> a[i], s += abs(a[i]), mi = min(mi, abs(a[i])), k += (a[i] < 0);
  if (n % 2)
    cout << s << endl;
  else {
    if (k % 2 == 0)
      cout << s << endl;
    else
      cout << s - mi * 2 << endl;
  }
  return 0;
}
