#include <bits/stdc++.h>
using namespace std;
int arr[105];
int main() {
  int n;
  cin >> n;
  int pos = 0;
  int neg = 0;
  int z = 0;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    if (arr[i] > 0)
      pos++;
    else if (arr[i] < 0)
      neg++;
    else
      z++;
  }
  int pas = 0;
  if (n % 2 == 0)
    pas = n / 2;
  else
    pas = (n / 2) + 1;
  int maxi = pos;
  if (neg > pos) maxi = neg;
  if (maxi >= pas && maxi == pos) {
    cout << 1 << endl;
  } else if (maxi >= pas && maxi == neg) {
    cout << -1 << endl;
  } else {
    cout << 0 << endl;
  }
  return 0;
}
