#include <bits/stdc++.h>
using namespace std;
int n, a[500], ans;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.setf(ios::fixed);
  cout.precision(20);
  cin >> n;
  int m = 2 * n - 1;
  for (int i = 0; i < m; ++i) cin >> a[i];
  int num = 0;
  for (int i = 0; i < m; ++i)
    if (a[i] < 0) ++num;
  for (int i = 0; i < m; ++i) a[i] = abs(a[i]);
  sort(a, a + m);
  for (int i = 0; i < m; ++i) ans += a[i];
  if (n % 2 == 0 && num % 2 == 1) {
    cout << ans - a[0] * 2 << '\n';
  } else {
    cout << ans << '\n';
  }
}
