#include <bits/stdc++.h>
using namespace std;
bool cmp(int a, int b) { return abs(a) < abs(b); }
int main() {
  int br = 0, i, n, a[300], s = 0;
  cin >> n;
  for (i = 1; i < n * 2; i++) {
    cin >> a[i];
    if (a[i] >= 0) br++;
  }
  sort(a + 1, a + n * 2, cmp);
  if (n % 2 == 0 && br % 2 == 0)
    br = n * 2 - 2;
  else
    br = n * 2 - 1;
  for (i = n * 2 - 1; br > 0; i--, br--) s += abs(a[i]);
  for (i; i > 0; i--) s -= abs(a[i]);
  cout << s << endl;
}
