#include <bits/stdc++.h>
using namespace std;
int cmp(const void* a, const void* b) { return *(int*)b - *(int*)a; }
int main() {
  int n, num1[210];
  signed int num;
  cin >> n;
  int i, k = 0;
  memset(num1, 0, sizeof(num1));
  for (i = 1; i <= 2 * n - 1; i++) {
    cin >> num;
    if (num >= 0)
      num1[i] = num;
    else
      k++, num1[i] = -num;
  }
  qsort(num1 + 1, 2 * n - 1, sizeof(int), cmp);
  int sum = 0;
  if (n % 2)
    for (i = 1; i <= 2 * n - 1; i++) sum += num1[i];
  else if (k % 2) {
    for (i = 1; i < 2 * n - 1; i++) sum += num1[i];
    sum -= num1[2 * n - 1];
  } else
    for (i = 1; i <= 2 * n - 1; i++) sum += num1[i];
  printf("%d\n", sum);
  return 0;
}
