#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long double E = 1e-7;
char ccc;
bool _minus = false;
inline void read(int &n) {
  n = 0;
  _minus = false;
  while (true) {
    ccc = getchar();
    if (ccc == ' ' || ccc == '\n') break;
    if (ccc == '-') {
      _minus = true;
      continue;
    }
    n = n * 10 + ccc - '0';
  }
  if (_minus) n *= -1;
}
char wwww[12];
int kkkk;
inline void write(int x) {
  kkkk = 0;
  if (!x) ++kkkk, wwww[kkkk] = '0';
  while (x) {
    ++kkkk;
    wwww[kkkk] = char(x % 10 + '0');
    x /= 10;
  }
  for (int i = kkkk; i >= 1; --i) putchar(wwww[i]);
  putchar('\n');
}
template <typename T>
inline T sqr(T t) {
  return t * t;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  srand(time(NULL));
  cout.precision(15);
  cout << fixed;
  int n;
  cin >> n;
  vector<int> v;
  int minuses = 0;
  for (int i = 1; i < n * 2; i++) {
    int t;
    cin >> t;
    if (t < 0) {
      minuses++;
    }
    v.push_back(abs(t));
  }
  sort(v.begin(), v.end());
  minuses &= 1;
  if (n & 1) minuses = 0;
  int ans = (minuses ? -v[0] : 0);
  for (int i = minuses; i < (int)v.size(); i++) {
    ans += v[i];
  }
  cout << ans << endl;
}
