#include <bits/stdc++.h>
using namespace std;
int n, cnt;
int sum, mn = 10000;
int s, e;
int main() {
  int a;
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> a;
    if (a < 0) cnt++;
    sum += abs(a);
    mn = min(mn, abs(a));
    if (i == 0) s = abs(a);
    if (i == 2 * n - 2) e = abs(a);
  }
  if (cnt % 2 == 0 || n % 2 == 1)
    cout << sum << endl;
  else
    cout << sum - 2 * mn << endl;
  return 0;
}
