#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n, a, i, sum = 0, k, mc = 0, min = 100000, minp;
  cin >> n;
  for (i = 0; i < 2 * n - 1; i++) {
    cin >> a;
    if (a < 0) {
      mc++;
      a = -a;
    }
    sum += a;
    if (a < min) min = a;
  }
  if (mc % 2 == 1 && n % 2 == 0) sum -= 2 * min;
  cout << sum;
  return 0;
}
