#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> a(n);
  int cnt = 0;
  int neg = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (a[i] > 0)
      cnt++;
    else if (a[i] < 0) {
      neg++;
    }
  }
  if (cnt >= (n + 1) / 2) {
    cout << 1 << endl;
  } else if (neg >= (n + 1) / 2) {
    cout << -1 << endl;
  } else {
    cout << 0 << endl;
  }
  return 0;
}
