#include <bits/stdc++.h>
using namespace std;
const long long A = 100000000000000LL, N = 228228;
long long T = 1000, i, j, n, m, o = -A, ot, a[N], ok;
int main() {
  cin >> n, m = n * 2 - 1;
  for (i = 0; i < m; i++) cin >> a[i], ot += a[i];
  o = max(o, ot);
  sort(a, a + m);
  if (n % 2) {
    for (i = 0; i < m; i++)
      if (a[i] < 0) ot += a[i] * -2;
    o = max(ot, o);
  } else {
    i = 0;
    while (i + 1 < m) {
      ot += a[i] * -2, i++, ot += a[i] * -2, i++;
      if (ot > o)
        o = ot;
      else
        break;
    }
  }
  cout << o << "\n";
}
