#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
void solve() {
  long long n, m, i, j, k, l, r, x, y, z, a, b, c;
  cin >> n;
  long long mn = 1000;
  int cnt = 0;
  long long sum = 0;
  for (i = 0; i < 2 * n - 1; i++) {
    cin >> a;
    if (a < 0) cnt++;
    mn = min(mn, abs(a));
    sum += abs(a);
  }
  if (cnt % 2 == 1 && n % 2 == 0) {
    sum -= 2 * mn;
  }
  cout << sum << "\n";
}
int main() {
  int t;
  solve();
}
