#include <bits/stdc++.h>
using namespace std;
long long rdtsc() {
  long long tmp;
  asm("rdtsc" : "=A"(tmp));
  return tmp;
}
const int maxm = 200;
int a[maxm];
int main() {
  srand(rdtsc());
  int n;
  while (scanf("%d", &n) >= 1) {
    int m = 2 * n - 1;
    int cnt = 0;
    for (int i = 0; i < m; i++) {
      scanf("%d", &a[i]);
      if (a[i] > 0)
        cnt++;
      else
        a[i] = -a[i];
    }
    sort(a, a + m);
    reverse(a, a + m);
    if (!(n & 1) && !(cnt & 1))
      cnt = m - 1;
    else
      cnt = m;
    int sum = 0;
    for (int i = 0; i < m; i++) {
      if (i < cnt)
        sum += a[i];
      else
        sum -= a[i];
    }
    printf("%d\n", sum);
  }
  return 0;
}
