#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  long long n;
  cin >> n;
  vector<long long> v(n);
  for (long long &i : v) cin >> i;
  long long pcnt, ocnt;
  pcnt = ocnt = 0;
  for (long long &i : v) {
    if (i > 0) pcnt++;
    if (i < 0) ocnt++;
  }
  long long nd = (n + 1) / 2;
  if (pcnt >= nd) {
    cout << 10;
  } else if (ocnt >= nd) {
    cout << -10;
  } else {
    cout << 0;
  }
  return 0;
}
