#include <bits/stdc++.h>
using namespace std;
set<string> st;
set<string>::iterator it;
vector<long long> v, vv;
int main() {
  int n, a[100000], cnt = 0, cnt2 = 0, k;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (a[i] > 0)
      cnt++;
    else if (a[i] < 0)
      cnt2++;
  }
  if (n % 2 == 0)
    k = n / 2;
  else
    k = (n / 2) + 1;
  if (cnt > cnt2) {
    if (cnt >= k)
      cout << 2 << endl;
    else
      cout << 0 << endl;
  } else {
    if (cnt2 >= k)
      cout << -2 << endl;
    else
      cout << 0 << endl;
  }
  return 0;
}
