#include <bits/stdc++.h>
using namespace std;
int n, ted = 0, ans = 0, x = (int)(1e8), y;
int main() {
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    cin >> y;
    if (y < 0) {
      ted++;
      y *= -1;
    }
    ans += y;
    x = min(x, y);
  }
  if (ted % 2 and !(n % 2)) ans -= 2 * x;
  cout << ans << endl;
}
