#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int sum = 0, lowest = 1023456789, negative = 0;
  for (int i = 0; i < (int)(2 * n - 1); ++i) {
    int a;
    cin >> a;
    if (a < 0) {
      ++negative;
      a *= -1;
    }
    sum += a;
    lowest = min(lowest, a);
  }
  if (n % 2 == 1 || negative % 2 == 0) {
    cout << sum << endl;
  } else {
    cout << sum - 2 * lowest << endl;
  }
}
