#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a = 0, b = 0;
  cin >> n;
  int t[n];
  for (int i = 0; i < n; i++) {
    cin >> t[i];
    if (t[i] > 0) a++;
    if (t[i] < 0) b++;
  }
  int c = ceil(n / 2.0);
  if (c > max(a, b))
    cout << 0 << endl;
  else {
    if (a > b)
      cout << 2 << endl;
    else
      cout << -2 << endl;
  }
  return 0;
}
