#include <bits/stdc++.h>
using namespace std;
int a[10000];
int main() {
  int n;
  cin >> n;
  int l = 2 * n - 1;
  for (int i = 0; i < l; i++) cin >> a[i];
  int neg = 0, sum = 0;
  for (int i = 0; i < l; i++) {
    if (a[i] < 0) neg++;
    sum += abs(a[i]);
  }
  if (n % 2 == 1 || neg % 2 == 0)
    cout << sum << endl;
  else {
    int min = 10000;
    for (int i = 0; i < l; i++)
      if (abs(a[i]) < min) min = abs(a[i]);
    cout << sum - 2 * min << endl;
  }
}
