#include <bits/stdc++.h>
using namespace std;
int n, m, k, t;
int s[100005];
int cnt = 0;
bool _cmp(int a, int b) { return abs(a) < abs(b); }
int solve() {
  int ret = 0;
  sort(s, s + 2 * n - 1, _cmp);
  if (cnt % 2 == 0)
    cnt = 0;
  else if (n % 2 == 1)
    cnt = 0;
  else
    cnt = 1;
  for (int i = 0; i < cnt; i++) ret += -abs(s[i]);
  for (int i = cnt; i < 2 * n - 1; i++) ret += abs(s[i]);
  return ret;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < (2 * n - 1); i++) {
    scanf("%d", s + i);
    if (s[i] < 0) cnt++;
  }
  printf("%d\n", solve());
  return 0;
}
