#include <bits/stdc++.h>
using namespace std;
int abs(int x) { return x < 0 ? -x : x; }
int tri[205];
int main() {
  int n, num = 0, sum = 0;
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> tri[i];
    if (tri[i] < 0) num++;
    tri[i] = abs(tri[i]);
    sum += tri[i];
  }
  sort(tri, tri + 2 * n - 1);
  if (n & 1)
    cout << sum << endl;
  else {
    if (num % 2 && num) sum -= 2 * tri[0];
    cout << sum << endl;
  }
  return 0;
}
