#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5;
const int inf = 1e9;
int a[maxn];
int main() {
  int n, sum = 0, cnt = 0, mn = inf;
  scanf("%d", &n);
  for (int i = 0; i < n * 2 - 1; i++) {
    scanf("%d", &a[i]);
    sum += abs(a[i]);
    cnt += a[i] < 0;
    mn = min(mn, abs(a[i]));
  }
  if (n % 2 == 0) {
    if (cnt % 2 == 1)
      printf("%d\n", sum - mn * 2);
    else
      printf("%d\n", sum);
  } else {
    printf("%d\n", sum);
  }
  return 0;
}
