5504：GT and sequence

You are given a sequence of $N$ integers.

You should choose some numbers(at least one),and make the product of them as big as possible.

It guaranteed that **the absolute value of** any product of the numbers you choose in the initial sequence will not bigger than $2^{63}-1$.

In the first line there is a number $T$ (test numbers).

For each test,in the first line there is a number $N$,and in the next line there are $N$ numbers.

$1 \leq T \leq 1000$
$1 \leq N \leq 62$

You'd better print the enter in the last line when you hack others.

You'd better not print space in the last of each line when you hack others.

For each test case,output the answer.