#include <bits/stdc++.h>
using namespace std;
const int maxn = 110;
int num[maxn];
int main(void) {
  int n;
  cin >> n;
  int pos = 0, neg = 0;
  for (int i = 1; i <= n; i++) {
    cin >> num[i];
    if (num[i] > 0) pos++;
    if (num[i] < 0) neg++;
  }
  if (pos < (n + 1) / 2 && neg < (n + 1) / 2)
    cout << "0\n";
  else if (pos >= (n + 1) / 2)
    cout << "1\n";
  else
    cout << "-1\n";
}
