#include <bits/stdc++.h>
using namespace std;
int n, K, Ans, Cnt;
int a[10005];
bool cmp(const int &i, const int &j) { return abs(i) > abs(j); }
int main() {
  scanf("%d", &n);
  K = n;
  n = 2 * n - 1;
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
  sort(a + 1, a + 1 + n, cmp);
  for (int i = 1; i <= n; i++) Ans += abs(a[i]);
  for (int i = 1; i <= n; i++) Cnt += a[i] < 0;
  if (Cnt % 2 && K % 2 == 0) Ans -= 2 * abs(a[n]);
  printf("%d\n", Ans);
}
