#include <bits/stdc++.h>
using namespace std;
const int N = 105;
int n, tot, a[N << 1];
void run() {
  int sum = 0, flag = 0;
  cin >> n;
  tot = n * 2 - 1;
  for (int i = 0; i < (tot); i++) {
    cin >> a[i];
    if (a[i] < 0) {
      a[i] = -a[i];
      flag++;
    }
    sum += a[i];
  }
  sort(a, a + tot);
  if (flag % 2 == 0 || (flag % 2 == 1 && n % 2 == 1))
    cout << sum << endl;
  else
    cout << sum - 2 * a[0] << endl;
}
int main() {
  run();
  return 0;
}
