#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, t, i, k, s, max;
  while (~scanf("%d", &n)) {
    t = 0;
    s = 0;
    m = 2 * n - 1;
    max = 0x7fffffff;
    for (i = 0; i < m; i++) {
      scanf("%d", &k);
      if (k < 0) t++;
      s += fabs(k);
      if (max > fabs(k)) max = fabs(k);
    }
    if ((n % 2 == 1) || (t % 2 == 0) || (t >= n && (t - n) % 2 == 0))
      printf("%d\n", s);
    else
      printf("%d\n", s - 2 * max);
  }
  return 0;
}
