#include <bits/stdc++.h>
using namespace std;
int n;
int ary[300];
int main() {
  while (~scanf("%d", &n)) {
    int sum = 0, min = 9999, num = 0;
    for (int i = 1; i <= 2 * n - 1; i++) {
      int a;
      scanf("%d", &a);
      if (a < 0) {
        a = -a;
        num++;
      }
      if (min > a) min = a;
      sum += a;
    }
    if (num % 2 && n % 2 == 0) sum -= 2 * min;
    printf("%d\n", sum);
  }
}
