#include <bits/stdc++.h>
using namespace std;
int n, nn = 0, pp = 0;
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    int x;
    scanf("%d", &x);
    if (x < 0)
      nn++;
    else if (x > 0)
      pp++;
  }
  if (nn >= n / 2 + n % 2)
    printf("-1");
  else if (pp >= n / 2 + n % 2)
    printf("1");
  else
    printf("0");
  return 0;
}
