#include <bits/stdc++.h>
using namespace std;
const long long inf = INT_MAX;
const int mod = 1e9 + 7;
bool cmp(const int a, const int b) { return abs(a) < abs(b); }
void solve() {
  int n;
  cin >> n;
  vector<int> a(2 * n - 1);
  int ng = 0;
  int s = 0;
  for (auto &x : (a)) {
    cin >> x;
    if (x < 0) ng++;
    s += abs(x);
  }
  sort((a).begin(), (a).end(), cmp);
  if (n % 2 == 0 && ng % 2 == 1) {
    cout << s - 2 * abs(a[0]) << endl;
    return;
  }
  cout << s << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
