#include <bits/stdc++.h>
using namespace std;
int n;
int num[300];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= 2 * n - 1; ++i) scanf("%d", &num[i]);
  sort(num + 1, num + 2 * n - 1 + 1);
  if (n & 1) {
    int ans = 0;
    for (int i = 1; i <= n * 2 - 1; ++i)
      if (num[i] < 0)
        ans += -num[i];
      else
        ans += num[i];
    printf("%d\n", ans);
  } else {
    for (int i = 1; i < n; ++i)
      if (num[i * 2 - 1] + num[i * 2] < 0) {
        num[i * 2 - 1] = -num[i * 2 - 1];
        num[i * 2] = -num[i * 2];
      }
    int ans = 0;
    for (int i = 1; i <= 2 * n - 1; ++i) ans += num[i];
    printf("%d\n", ans);
  }
  return 0;
}
