#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, cnt = 0, cnt1 = 0, cnt2 = 0, p;
  cin >> n;
  p = (n + 1) / 2;
  for (int i = 1; i <= n; i++) {
    cin >> a;
    if (a > 0) cnt++;
    if (a < 0) cnt1++;
    if (a != 0) cnt2++;
  }
  if (cnt >= p)
    cout << 1 << endl;
  else if (cnt1 >= p)
    cout << -1 << endl;
  else
    cout << 0 << endl;
  return 0;
}
