#include <bits/stdc++.h>
using namespace std;
int as[1005];
int main() {
  int i, n, j, sum, k;
  while (scanf("%d", &n) != EOF) {
    k = 2 * n - 1;
    j = 0;
    for (i = 0; i < k; i++) {
      scanf("%d", &as[i]);
      if (as[i] < 0) j++;
    }
    for (i = 0; i < 2 * n - 1; i++) as[i] = abs(as[i]);
    sum = 0;
    sort(as, as + k);
    for (i = 0; i < k; i++) sum += as[i];
    if ((n % 2 == 0) && (j % 2 == 1)) sum -= 2 * as[0];
    printf("%d\n", sum);
  }
  return 0;
}
