#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, mini, ans = 0, t = 0, p;
  cin >> n;
  int arr[n * 2 - 1];
  for (i = 0; i < 2 * n - 1; i++) {
    cin >> p;
    if (p < 0) {
      t++;
      arr[i] = -1 * p;
    } else
      arr[i] = p;
  }
  mini = arr[0];
  for (i = 0; i < n * 2 - 1; i++) {
    ans += arr[i];
    if (arr[i] < mini) mini = arr[i];
  }
  t %= n;
  if (t % 2 == 0 || (n - t) % 2 == 0)
    cout << ans;
  else
    cout << ans - 2 * mini;
}
