#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int u;
  while (scanf("%d", &n) != EOF) {
    int ans = 0;
    int neg = 0;
    int mi = 100000;
    int zero = 0;
    for (int i = 1; i <= 2 * n - 1; ++i) {
      scanf("%d", &u);
      if (u == 0) zero = 1;
      if (u < 0) neg++;
      ans += abs(u);
      if (mi > abs(u)) mi = abs(u);
    }
    if (neg % 2 && n % 2 == 0) {
      if (!zero) ans -= 2 * mi;
    }
    printf("%d\n", ans);
  }
  return 0;
}
