#include <bits/stdc++.h>
using namespace std;
const int Maxn = 100 + 19;
int A[Maxn * 2], n, _n, sum;
int main() {
  scanf("%d", &_n);
  n = _n * 2 - 1;
  for (int i = 0; i < n; i++) scanf("%d", &A[i]);
  sort(A, A + n);
  if (_n % 2 == 0) {
    int x = 0;
    while (x + 1 < n) {
      if (-A[x] - A[x + 1] > 0)
        sum += -A[x] - A[x + 1];
      else
        sum += A[x] + A[x + 1];
      x += 2;
    }
    sum += A[n - 1];
  } else
    for (int i = 0; i < n; i++) sum += abs(A[i]);
  printf("%d\n", sum);
}
