#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, cnt = 0, sum = 0;
  vector<int> a;
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> k;
    if (k < 0) {
      cnt++;
      k = -k;
    }
    sum += k;
    a.push_back(k);
  }
  sort(a.begin(), a.end());
  if (!(n & 1) && (cnt & 1)) sum -= 2 * a[0];
  cout << sum;
}
