#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, mn = 100000, sum = 0, gas = 0, nn;
  scanf("%d", &n);
  nn = 2 * n - 1;
  while (nn--) {
    scanf("%d", &a);
    sum += abs(a);
    mn = min(mn, abs(a));
    if (a < 0) gas++;
  }
  if (n & 1) {
    printf("%d", sum);
    return 0;
  }
  if (gas & 1) {
    printf("%d", sum - 2 * mn);
    return 0;
  }
  printf("%d", sum);
}
