#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 545;
int a[MAX_N];
int main() {
  int n, minus = 0;
  cin >> n;
  int sum = 0;
  for (int i = (0); i < (int)(2 * n - 1); ++i) {
    cin >> a[i];
    if (a[i] < 0) {
      a[i] = abs(a[i]);
      minus++;
    }
    sum += a[i];
  }
  sort(a, a + (2 * n) - 1);
  if (n % 2 == 0 && minus % 2) sum -= (a[0] * 2);
  cout << sum << endl;
  return 0;
}
