#include <bits/stdc++.h>
using namespace std;
int ar[300];
int main() {
  int n;
  cin >> n;
  int minus = 0;
  int min = 2000;
  for (int i = 0; i < 2 * n - 1; ++i) {
    cin >> ar[i];
    if (ar[i] < 0) {
      minus++;
      ar[i] = -ar[i];
    }
    if (ar[i] < min) min = ar[i];
  }
  int sum = 0;
  if (minus % 2 == 0 || n % 2 == 1) {
    for (int i = 0; i < 2 * n - 1; ++i) sum += ar[i];
    cout << sum;
    return 0;
  }
  for (int i = 0; i < 2 * n - 1; ++i) {
    sum += ar[i];
  }
  cout << sum - 2 * min;
  return 0;
}
