#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, minus, m, a, s = 0, z = 0;
  cin >> n;
  m = 1001;
  for (i = 1; i <= 2 * n - 1; i++) {
    cin >> a;
    if (a < 0) minus++;
    s += abs(a);
    m = min(m, abs(a));
    if (a == 0) z = 1;
  }
  if (n % 2 == 1)
    cout << s;
  else if (z == 1)
    cout << s;
  else if (minus % 2 == 1)
    cout << s - 2 * m;
  else
    cout << s;
  return 0;
}
