#include <bits/stdc++.h>
const int N = 1e6 + 5;
long long a[N];
int main() {
  long long n;
  while (~scanf("%lld", &n)) {
    long long af = 0;
    long long sum = 0;
    long long mina = 1e10 + 5;
    for (long long i = 0; i < 2 * n - 1; i++) {
      scanf("%lld", &a[i]);
      if (a[i] < 0) {
        a[i] = -a[i];
        af++;
      }
      if (a[i] < mina) mina = a[i];
      sum += a[i];
    }
    if (n % 2 == 1 || af % 2 == 0)
      printf("%lld\n", sum);
    else
      printf("%lld\n", sum - 2 * mina);
  }
  return 0;
}
