#include <bits/stdc++.h>
using namespace std;
const int delta = (long long)1e9 + 7;
int n, a, mi = 1e18 + 20, x, s;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  for (int i = 0; i < 2 * n - 1; ++i) {
    cin >> a;
    if (a < 0) {
      x++;
      a *= -1;
    }
    s += a;
    mi = min(mi, a);
  }
  if (n % 2 == 0 && x % 2 == 1) s -= 2 * mi;
  cout << s;
  return cout << endl, 0;
}
