#include <bits/stdc++.h>
using namespace std;
int a[210];
int n1, n2;
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < (2 * n - 1); ++i) {
    int in;
    cin >> in;
    if (in >= 0) {
      a[i] = in;
      n1++;
    } else {
      a[i] = -in;
      n2++;
    }
  }
  int ans = 0;
  if (n % 2 == 1 || n2 % 2 == 0) {
    for (int i = 0; i < (2 * n - 1); ++i) ans += a[i];
    cout << ans << endl;
    return 0;
  }
  sort(a, a + 2 * n - 1, greater<int>());
  for (int i = 0; i < (2 * n - 2); ++i) ans += a[i];
  cout << ans - a[2 * n - 2] << endl;
  return 0;
}
