#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, s;
  cin >> n;
  vector<long long> vc;
  for (long long i = 0; i < n; i++) {
    cin >> s;
    vc.push_back(s);
  }
  long long cntp = 0, cntn = 0;
  long long p = ceil(n * 1.0 / 2.0);
  for (long long i = 0; i < (long long)((vc).size()); i++) {
    if (vc[i] > 0) cntp++;
    if (vc[i] < 0) cntn++;
  }
  if (cntp >= p) {
    cout << "5";
    return 0;
  }
  if (cntn >= p) {
    cout << "-1";
    return 0;
  }
  cout << "0\n";
  return 0;
}
