#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, minn = 100000, sum, cnt;
  while (scanf("%d", &n) == 1) {
    sum = 0, cnt = 0;
    for (int i = 0; i < (2 * n) - 1; i++) {
      scanf("%d", &a);
      if (a < 0) {
        sum += -a;
        cnt++;
        a = -a;
        minn = min(minn, a);
      } else {
        sum += a;
        minn = min(minn, a);
      }
    }
    if (n % 2 == 1)
      printf("%d\n", sum);
    else {
      if (cnt % 2 == 1)
        printf("%d\n", sum - 2 * minn);
      else
        printf("%d\n", sum);
    }
  }
  return 0;
}
