Problem:
Score : 200 points

Problem Statement

Given N integers A_1, ..., A_N, compute A_1 \times ... \times A_N.

However, if the result exceeds 10^{18}, print -1 instead.

Constraints

2 \leq N \leq 10^5

0 \leq A_i \leq 10^{18}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 ... A_N

Output

Print the value A_1 \times ... \times A_N as an integer, or -1 if the value exceeds 10^{18}.

Sample Input 1

2
1000000000 1000000000

Sample Output 1

1000000000000000000

We have 1000000000 \times 1000000000 = 1000000000000000000.

Sample Input 2

3
101 9901 999999000001

Sample Output 2

-1

We have 101 \times 9901 \times 999999000001 = 1000000000000000001, which exceeds 10^{18}, so we should print -1 instead.

Sample Input 3

31
4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6 2 6 4 3 3 8 3 2 7 9 5 0

Sample Output 3

0

Solution in Common Lisp (SBCL 2.0.3) (judge verdict: Accepted)

;;(declaim (optimize (speed 0) (safety 3) (debug 3)))
(declaim (optimize (speed 3) (safety 0) (debug 0)))

(defvar *n* (read))
(defvar arr (make-array *n*))
(dotimes (i *n*) (setf (aref arr i) (read)))

(let ((i 0) (p 1))
  (loop for j from 0 below *n*
	for a = (aref arr j)
	when (> p 1000000000000000000) do (return)
	do (setf p (* p a)) (incf i))
  (loop for j from i below *n*
	for a = (aref arr j)
	when (= a 0) do (setf p 0))
  (princ (if (> p 1000000000000000000) -1 p)))