#include <bits/stdc++.h>
#pragma warning(disable : 4996)
int main() {
  int casenumber = 0;
  int number[100] = {0};
  int lab = 0;
  while (scanf("%d", &casenumber) != EOF) {
    for (lab = 0; lab < casenumber; lab++) {
      scanf("%d", &number[lab]);
    }
    int len = casenumber / 2;
    if (casenumber % 2 != 0) {
      len++;
    }
    int rec = len;
    int divided = ++len;
    int pos = 0, nev = 0;
    for (int i = 0; i < casenumber; i++) {
      if (number[i] / divided > 0) {
        pos++;
      } else if (number[i] / (divided * (-1)) > 0) {
        nev++;
      } else if (number[i] / divided == 0) {
        if (number[i] % divided != 0 && number[i] % divided > 0) {
          pos++;
        } else if (number[i] % divided != 0 && number[i] % divided < 0) {
          nev++;
        }
      }
    }
    if (pos >= rec) {
      printf("%d\n", divided);
    } else if (nev >= rec) {
      printf("%d\n", divided * (-1));
    } else
      printf("0\n");
  }
  return 0;
}
