#include <bits/stdc++.h>
int s[205];
int num, totalnum, nnum = 0;
int totalsum = 0;
int fab(int a) { return a > 0 ? a : -a; }
int cmp(const void *a, const void *b) {
  return fab(*(int *)a) - fab(*(int *)b);
}
int main() {
  scanf("%d", &num);
  totalnum = 2 * num - 1;
  int i;
  for (i = 0; i < totalnum; i++) {
    scanf("%d", &s[i]);
    if (s[i] < 0) nnum++;
  }
  qsort(s, totalnum, sizeof(s[0]), cmp);
  for (i = 0; i < totalnum; i++) s[i] = fab(s[i]);
  if (num % 2 == 0 && nnum % 2 != 0) s[0] = -s[0];
  for (i = 0; i < totalnum; i++) totalsum += s[i];
  printf("%d\n", totalsum);
  return 0;
}
