#include <bits/stdc++.h>
using namespace std;
const int maxn = 210;
int a[maxn];
int sum, mn = 11111, manfi = 0;
int n;
int main() {
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> a[i];
    if (a[i] < 0) manfi++;
    sum += abs(a[i]);
    mn = min(mn, abs(a[i]));
  }
  if (n % 2 == 0 && manfi % 2 == 1)
    cout << sum - 2 * mn;
  else
    cout << sum;
  cout << endl;
  return 0;
}
