CF1130A Be Positive

有一个包含nnn个整数的数组,你需要找到一个非零整数$d(-10^3\leq d \leq 10^3)$，使数组中的每一个数组除以d的商中至少有一半为正数(即至少有$\frac{n}{2}$个)注意:"正数"只要求商大于0,不要求一定是整数。如果有多个$d$满足条件，输出其中的任意一个,如果没有这样的$d$则输出$0$。

第一行包含一个整数$n$,表示数组中元素的数量 第二行包含由$n$个整数,数之间由一个空格隔开。$a_1,a_2,a_3,...,a_n(-10^3\leq a_i \leq 10^3)$

Print one integer $ d $ ( $ -10^3 \leq d \leq 10^3 $ and $ d \neq 0 $ ) that satisfies the given condition. If there are multiple values of $ d $ that satisfy the condition, you may print any of them. In case that there is no such $ d $ , print a single integer $ 0 $ .

In the first sample, $ n = 5 $ , so we need at least $ \lceil\frac{5}{2}\rceil = 3 $ positive numbers after division. If $ d = 4 $ , the array after division is $ [2.5, 0, -1.75, 0.5, 1.5] $ , in which there are $ 3 $ positive numbers (namely: $ 2.5 $ , $ 0.5 $ , and $ 1.5 $ ). In the second sample, there is no valid $ d $ , so $ 0 $ should be printed.