#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int x, i, m = 0, p = 0;
  for (i = 0; i < n; i++) {
    cin >> x;
    if (x > 0) m++;
    if (x < 0) p++;
  }
  if (n % 2 != 0) {
    if (p > n / 2)
      cout << -2;
    else if (m > n / 2)
      cout << 2;
    else
      cout << 0;
  } else {
    if (p >= n / 2)
      cout << -2;
    else if (m >= n / 2)
      cout << 2;
    else
      cout << 0;
  }
  return 0;
}
