#include <bits/stdc++.h>
using namespace std;
int x, mi = 1001, n, sum, k;
int main() {
  cin >> n;
  for (int i = 1; i <= n + n - 1; i++) {
    cin >> x;
    sum += abs(x);
    if (x < 0) k++;
    mi = min(mi, abs(x));
  }
  if (n % 2)
    cout << sum;
  else if (k % 2 == 0)
    cout << sum;
  else
    cout << sum - mi - mi;
  return 0;
}
