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 Fortran (GNU Fortran 9.2.1) (judge verdict: Wrong Answer)

program mondai2
implicit none
integer*8 i, n, b
integer*8 a(100000)
b = 1
i = 1
read(*,*) n
read(*,*) (a(i), i=1,n)
i = 1
do while (i<=n)
  if (a(i) == 0)then
    b = 0
    exit
  end if
  b = b * a(i)
  i = i + 1
  if (dble(b) / 10.0 ** 18.0 > 1) then
    b = -1
    exit
  end if	
end do

write(*,*) int(b)
end program mondai2