#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int arr[2 * n + 1];
  int m = n;
  n = 2 * n - 1;
  int ans = 0, mi = 9999, pans = 0, p = 0;
  for (int i = 0; i < n; i++) cin >> arr[i];
  for (int i = 0; i < n; i++) mi = min(mi, abs(arr[i]));
  for (int i = 0; i < n; i++) ans += abs(arr[i]);
  for (int i = 0; i < n; i++) pans += arr[i];
  for (int i = 0; i < n; i++)
    if (arr[i] < 0) p++;
  if (m % 2)
    cout << ans;
  else if (p % 2 == 0)
    cout << ans;
  else
    cout << max(ans - 2 * mi, pans);
}
