#include <bits/stdc++.h>
using namespace std;
int a[120 * 2] = {0}, b[120] = {0};
int getsum(int n) {
  int sum = 0;
  for (int i = 0; i < n; i++) sum += abs(a[i]);
  return sum;
}
int main() {
  int n;
  cin >> n;
  int cou = 0;
  for (int i = 0; i < n * 2 - 1; i++) {
    cin >> a[i];
    if (a[i] < 0) {
      cou++;
      a[i] = -a[i];
    }
  }
  sort(a, a + n * 2 - 1);
  int sum = getsum(n * 2 - 1);
  if ((n % 2) || (cou % 2 == 0)) {
    cout << sum << endl;
  } else
    cout << sum - a[0] * 2 << endl;
}
