#include <bits/stdc++.h>
using namespace std;
int n, s;
int q[200];
int x, res;
int main() {
  cin >> n;
  s = 2 * n - 1;
  int i;
  for (i = 0; i < s; i++) {
    cin >> q[i];
    if (q[i] < 0) x++;
    if (q[i] < 0) q[i] = -q[i];
    res += q[i];
  }
  sort(q, q + s);
  if (x >= n) {
    x -= n;
  }
  if (n % 2 == 1 || x % 2 == 0)
    ;
  else
    res -= 2 * q[0];
  cout << res << endl;
  return 0;
}
