#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[200], n, i, s = 0;
  scanf("%d", &n);
  for (i = 0; i < 2 * n - 1; i++) {
    scanf("%d", &a[i]);
    if (a[i] < 0)
      s -= a[i];
    else
      s += a[i];
  }
  if (n % 2 == 0) {
    sort(a, a + 2 * n - 1);
    for (i = 0; i < 2 * n - 1; i++) {
      if (a[i] > 0) break;
    }
    if (i % 2 == 1) {
      if (a[i - 1] + a[i] < -a[i - 1] - a[i] || a[i] < 0)
        s -= fabs(2 * a[i]);
      else
        s += 2 * a[i - 1];
    }
  }
  cout << s << endl;
}
