#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  long long int n, m = 0, s = 0, a = 1000, x, i;
  cin >> n;
  for (i = 1; i < 2 * n; i++) {
    cin >> x;
    s += abs(x);
    if (x < 0) m++;
    if (abs(x) < a) a = abs(x);
  }
  if (m % 2 && n % 2 == 0)
    cout << s - 2 * a;
  else
    cout << s;
}
