#include <bits/stdc++.h>
using namespace std;
long long const maxx = 1e16 + 5;
long const md = 1000000007;
long const mx = 2147483647;
long const mm = 1743;
long n, i, j, k, l, a[500], x;
int main() {
  scanf("%d", &n);
  for (i = 1; i <= 2 * n - 1; i++) {
    scanf("%d", &a[i]);
    if (a[i] <= 0) x++;
  }
  l = 0;
  for (i = 1; i <= 2 * n - 1; i++) l += abs(a[i]);
  k = 0;
  if (x % 2 == 1 && n % 2 == 0) {
    k = mx;
    for (i = 1; i <= 2 * n - 1; i++)
      if (abs(a[i]) < k) k = abs(a[i]);
  }
  printf("%d", l - 2 * k);
}
