#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  scanf("%d", &n);
  m = 2 * n - 1;
  int sum = 0, mmi = 9999999, temp, con = 0, ze = 0;
  for (int i = 0; i < m; i++) {
    scanf("%d", &temp);
    mmi = min(abs(temp), mmi);
    if (temp == 0) ze = 1;
    if (temp < 0) con++;
    sum += abs(temp);
  }
  if ((n & 1) == 0) {
    if (ze == 0 && con % 2)
      printf("%d\n", sum - 2 * mmi);
    else
      printf("%d\n", sum);
  } else {
    printf("%d\n", sum);
  }
  return 0;
}
