#include <bits/stdc++.h>
using namespace std;
vector<int> a, b;
int main() {
  int n;
  scanf("%d", &n);
  int sum = 0, minn = 100000;
  for (int i = 0; i < 2 * n - 1; i++) {
    int x;
    scanf("%d", &x);
    if (x > 0)
      a.push_back(x);
    else if (x < 0)
      b.push_back(x);
    sum += abs(x);
    minn = min(minn, abs(x));
  }
  int cnt_1 = a.size(), cnt_2 = b.size(), cnt_0 = n - cnt_1 - cnt_2;
  if (n % 2 != 0 || cnt_2 % 2 == 0)
    printf("%d\n", sum);
  else {
    printf("%d\n", sum - 2 * minn);
  }
  return 0;
}
