#include <bits/stdc++.h>
using namespace std;
const long long MAXN = 2e5 + 1, INF = 1e9, MOD = 1e9 + 7;
long long n, sum, t, mn = INF;
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin >> n;
  for (long long i = 0; i < 2 * n - 1; ++i) {
    long long a;
    cin >> a;
    if (a < 0) t++;
    sum += abs(a);
    mn = min(abs(a), mn);
  }
  if (n % 2 == 0) {
    if (t % 2)
      cout << sum - 2 * mn << endl;
    else
      cout << sum << endl;
  } else {
    cout << sum << endl;
  }
  return 0;
}
