#include <bits/stdc++.h>
using namespace std;
const long long MAX = 1e6 + 8;
const long long sz = 1e5 + 5;
void f_io() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
}
bool comp(const pair<long long, long long>& a,
          const pair<long long, long long>& b) {
  return a.first < b.first;
}
int32_t main() {
  f_io();
  long long t = 1;
  while (t--) {
    long long n;
    cin >> n;
    vector<long long> v;
    long long sum = 0;
    long long cnt_neg = 0;
    long long k = 1e9;
    for (long long i = 1; i < 2 * n; i++) {
      long long temp;
      cin >> temp;
      v.push_back(abs(temp));
      cnt_neg += temp < 0;
      sum += abs(temp);
      k = min(k, abs(temp));
    }
    if (cnt_neg % 2 && n % 2 == 0) sum -= 2 * k;
    cout << sum << "\n";
  }
}
