#include <bits/stdc++.h>
using namespace std;
const long long N = 3e5 + 1, MOD = 1e9 + 7, MX = 1e9 + 7;
int m, T, k, n, a[N], neg, mn = MX;
long long sum, ans;
map<int, int> mp, vv;
string s;
vector<int> v;
vector<pair<char, int>> ss;
set<int> st;
bool vis[N], flag;
double mx, tmp;
int main() {
  cin >> n;
  for (int i = 0; i < 2 * n - 1; i++) {
    scanf("%d", a + i);
    neg += (a[i] < 0 ? 1 : 0);
    sum += abs(a[i]);
    mn = min(abs(a[i]), mn);
  }
  if (neg % 2 && !(n % 2)) sum -= 2 * mn;
  printf("%d\n", sum);
  return 0;
}
