#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  ;
  long long int n;
  cin >> n;
  long long int c = 0, sum = 0;
  long long int mn = 999999999999;
  for (long long int i = 0; i < 2 * n - 1; i++) {
    long long int x;
    cin >> x;
    if (x < 0) {
      x = -x;
      c++;
    }
    sum += x;
    mn = min(mn, x);
  }
  if (n % 2 == 0 and c % 2 == 1) sum -= 2 * mn;
  cout << sum;
  return 0;
}
