#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, sum = 0, k = 0;
  cin >> n;
  int m = 2 * n - 1;
  int a[m];
  for (int i = 0; i < m; i++) {
    cin >> a[i];
    if (a[i] < 0) {
      a[i] = a[i] * -1;
      k++;
    }
    sum = sum + a[i];
  }
  sort(a, a + m);
  if (n % 2 == 0) {
    if (k % 2 == 1) sum = sum - 2 * a[0];
  }
  cout << sum << endl;
}
