#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long int lcm(long long int a, long long int b) {
  return a * b / gcd(a, b);
}
long long int fexp(long long int a, long long int b) {
  long long int ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % 1000000007;
    b /= 2;
    a = a * a % 1000000007;
  }
  return ans;
}
long long int inverse(long long int a, long long int p) {
  return fexp(a, p - 2);
}
void ingraph(vector<vector<long long int> >& graph, long long int m) {
  long long int x, y;
  for (long long int i = 0; i < m; i++) {
    cin >> x >> y;
    x--, y--;
    graph[x].push_back(y);
    graph[y].push_back(x);
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long int t;
  t = 1;
  while (t--) {
    long long int n;
    cin >> n;
    long long int cnt = 0, x, mnev = 1000001, s = 0, mpos = 1000001;
    for (long long int i = 0; i < 2 * n - 1; i++) {
      cin >> x;
      if (x < 0) {
        cnt++;
        mnev = min(abs(x), mnev);
      } else {
        mpos = min(x, mpos);
      }
      s += abs(x);
    }
    if (cnt & 1 && !(n & 1))
      cout << s - 2 * min(mpos, mnev);
    else
      cout << s;
  }
}
