#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, res = 0, cp = 0, cn = 0, cz = 0;
  cin >> n;
  vector<long long> arr(n);
  for (long long i = 0; i < n; i++) {
    cin >> arr[i];
    if (arr[i] > 0)
      cp++;
    else if (arr[i] < 0)
      cn++;
    else
      cz++;
  }
  if (cp > (cn + cz)) {
    cout << "1";
  } else if (cn > (cp + cz)) {
    cout << "-1";
  } else {
    if (cp == (cn + cz) && n % 2 == 0)
      cout << "1";
    else if (cn == (cp + cz) && n % 2 == 0)
      cout << "-1";
    else
      cout << "0";
  }
  return 0;
}
