#include <bits/stdc++.h>
using namespace std;
const int INF = 1E9 + 7;
int main() {
  int n;
  cin >> n;
  int sum = 0;
  int mn = INF, cnt = 0;
  for (int i = 0; i < 2 * n - 1; ++i) {
    int x;
    cin >> x;
    sum += abs(x);
    mn = min(mn, abs(x));
    if (x < 0) ++cnt;
  }
  if (n % 2 == 0 && cnt % 2) sum -= 2 * mn;
  cout << sum;
}
