#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> a;
  for (int(i) = 0; (i) < (int)(2 * n - 1); ++(i)) {
    int x;
    cin >> x;
    a.push_back(x);
  }
  if (n % 2 == 0) {
    long long sum = 0;
    int f = 1;
    for (int(i) = 0; (i) < (int)(2 * n - 1); ++(i))
      f = a[i] == 0 ? 2 : f * (a[i] / abs(a[i])), sum += a[i] = abs(a[i]);
    sort((a).begin(), (a).end());
    if (f == -1) sum -= a[0] * 2;
    cout << sum << endl;
  } else {
    long long sum = 0;
    for (int(i) = 0; (i) < (int)(2 * n - 1); ++(i)) sum += abs(a[i]);
    cout << sum << endl;
  }
}
