#include <bits/stdc++.h>
using namespace std;
const int maxn = 2000 * 100 + 10, mod = 1000000007;
long long a[maxn];
multiset<long long> s;
vector<long long> v;
int main() {
  ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  int t;
  t = 1;
  while (t--) {
    long long n, mn = LLONG_MAX / 2, sum = 0, x = 0;
    cin >> n;
    bool f = 0;
    for (int i = 0; i < 2 * n - 1; i++) {
      cin >> a[i];
      if (a[i] >= 0) f = 1;
      sum += abs(a[i]);
      mn = min(mn, abs(a[i]));
      if (a[i] < 0) x++;
    }
    if (x % 2 && !(n % 2))
      cout << sum - 2 * mn << endl;
    else
      cout << sum << endl;
  }
  return 0;
}
