#include <bits/stdc++.h>
using namespace std;
int a[111];
int main() {
  int mx = 1000000000;
  int cnt, n;
  scanf("%d", &n);
  int sum = 0;
  cnt = 0;
  int k = 0;
  for (int i = 1; i < n * 2; ++i) {
    scanf("%d", &a[i]);
    sum += abs(a[i]);
    mx = ((mx) < (abs(a[i])) ? (mx) : (abs(a[i])));
    if (a[i] < 0) {
      cnt++;
    }
    if (a[i] == 0) k++;
  }
  if (cnt % 2 == 0 || n % 2 == 1 || k != 0)
    printf("%d\n", sum);
  else {
    printf("%d\n", sum - mx - mx);
  }
}
