#include <bits/stdc++.h>
using namespace std;
int n, temp, minimum = 1001, sum = 0, k = 0, size;
int main() {
  scanf("%d", &n);
  size = 2 * n - 1;
  for (int i = 0; i < size; i++) {
    scanf("%d", &temp);
    sum += abs(temp);
    if (temp < 0) k++;
    minimum = min(minimum, abs(temp));
  }
  if (n % 2)
    printf("%d\n", sum);
  else if ((k + 1) % 2)
    printf("%d\n", sum);
  else
    printf("%d\n", sum - 2 * minimum);
  return 0;
}
