#include <bits/stdc++.h>
using namespace std;
const long long int INF = 1e18;
const int inf = 1e9;
const int MOD = 1e9 + 7;
const int nax = 1000000 + 10;
int main() {
  ios::sync_with_stdio(0);
  int mini = inf;
  int n;
  cin >> n;
  long long int sum = 0;
  int flag = 0;
  for (int i = 1; i <= 2 * n - 1; i++) {
    int num;
    cin >> num;
    if (num < 0) flag++;
    mini = min(mini, abs(num));
    sum += abs(num);
  }
  if (flag == 0) {
    cout << sum << endl;
    return 0;
  }
  if (n % 2 == 1)
    cout << sum << endl;
  else {
    if (flag % 2 == 0)
      cout << sum << endl;
    else
      cout << sum - 2 * mini << endl;
  }
  return 0;
}
