#include <bits/stdc++.h>
using namespace std;
using namespace std;
long long powm(long long base, long long exp, long long mod = 1000000007) {
  long long ans = 1;
  while (exp) {
    if (exp & 1) ans = (ans * base) % mod;
    exp >>= 1, base = (base * base) % mod;
  }
  return ans;
}
int main() {
  long long tot = 0, n, x, cnt = 0, minm = 1000111000111000111LL;
  cin >> n;
  for (long long i = 0; i < 2 * n - 1; i++)
    cin >> x, cnt += (x < 0), x = abs(x), tot += x, minm = min(minm, x);
  if ((n % 2 == 1) or (cnt % 2 == 0))
    cout << tot;
  else
    cout << tot - 2 * minm;
  return 0;
}
