#include <bits/stdc++.h>
using namespace std;
string FILE_NAME = "testcase.C";
string NAME;
string itos(int n) {
  stringstream ss;
  ss << n;
  return ss.str();
}
int main() {
  int n;
  cin >> n;
  vector<int> a(2 * n - 1, 0);
  int m = 0;
  for (int i = 0; i < (2 * n - 1); i++) {
    cin >> a[i];
    if (a[i] > 0) m++;
  }
  sort(a.begin(), a.end());
  int sum = 0;
  for (int i = 0; i < (2 * n - 1); i++) {
    sum += abs(a[i]);
  }
  int min_all = 1 << 29;
  for (int i = 0; i < (2 * n - 1); i++) {
    int b = abs(a[i]);
    min_all = min(min_all, b);
  }
  if ((sum == accumulate(a.begin(), a.end(), 0)) || (n % 2 == 1) ||
      (m % 2 == 1)) {
    cout << sum << endl;
  } else {
    cout << sum - 2 * min_all << endl;
  }
  return 0;
}
