#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n) {
    int neg = 0, ans = 0;
    int num[200] = {0};
    for (int i = 0; i < 2 * n - 1; i++) {
      int interger;
      cin >> interger;
      if (interger < 0) {
        num[i] = -interger;
        neg++;
        ans += num[i];
      } else {
        num[i] = interger;
        ans += num[i];
      }
    }
    sort(num, num + 2 * n - 1);
    if (n % 2 == 1) {
      cout << ans << endl;
    } else {
      if (neg % 2 == 0)
        cout << ans << endl;
      else
        cout << ans - 2 * num[0] << endl;
    }
  }
  return 0;
}
