#include <bits/stdc++.h>
using namespace std;
int n, f[200], num, m, ans;
int main() {
  cin >> n;
  m = 2 * n - 1;
  for (int i = 0; i < m; i++) cin >> f[i];
  f[m] = 0;
  sort(f, f + m);
  num = 0;
  for (int i = 0; i < m; i++)
    if (f[i] < 0) num++;
  if (n % 2 == 1 || num % 2 == 0) {
    ans = 0;
    for (int i = 0; i < m; i++)
      if (f[i] < 0)
        ans -= f[i];
      else
        ans += f[i];
  } else if (num == m) {
    num--;
    ans = 0;
    for (int i = 0; i < num; i++) ans -= f[i];
    ans += f[m - 1];
  } else {
    num--;
    ans = 0;
    for (int i = 0; i < num; i++) ans -= f[i];
    if (f[num] + f[num + 1] < 0)
      ans -= f[num] + f[num + 1];
    else
      ans += f[num] + f[num + 1];
    for (int i = num + 2; i < m; i++) ans += f[i];
  }
  printf("%d\n", ans);
  return 0;
}
