#include <bits/stdc++.h>
using namespace std;
const int MAX = 109;
int a[MAX], n, k, t = 1e9, s;
int main() {
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> a[i], s += abs(a[i]), t = min(t, abs(a[i]));
    if (a[i] < 0) k++;
  }
  if (k % 2 && n % 2 == 0) s -= 2 * t;
  cout << s;
}
