#include <bits/stdc++.h>
using namespace std;
int n;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  int ans = 0, mn = 1e5, cnt = 0;
  for (int i = 0; i < 2 * n - 1; i++) {
    int val;
    cin >> val;
    if (val < 0) cnt++;
    ans += abs(val);
    mn = min(mn, abs(val));
  }
  if ((n % 2 == 0) and cnt % 2) ans -= 2 * mn;
  cout << ans << "\n";
  return 0;
}
