#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x, s = 0;
  cin >> n;
  vector<int> a(2 * n - 1);
  for (size_t i = 0; i < static_cast<size_t>(2 * n - 1); ++i) {
    cin >> a[i];
    if (a[i] < 0) {
      a[i] *= -1;
      ++x;
    }
    s += a[i];
  }
  sort(a.begin(), a.end());
  if (x % 2 == 1 && n % 2 == 0) {
    s -= a[0] * 2;
  }
  cout << s << endl;
  return 0;
}
