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: Accepted)

program main
  implicit none
  integer :: n
  integer(16), allocatable :: an(:)
  integer :: i
  integer(16) :: threshold, ans
  logical :: flag
  threshold = 1

  do i = 1, 18
    threshold = threshold * 10
  enddo

  read *, n
  allocate(an(n))
  read *, an(1:n)

  if (minval(an) == 0)then
    print "(i0)", 0
  else

    flag = .true.
    ans = 1
    do i = 1, n
      ans = ans * an(i)
      if (ans > threshold)then
        flag = .false.
        exit
      endif
    enddo

    if (flag)then
      print "(i0)", ans
    else
      print "(i0)", -1
    endif
  endif
end program