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 ABC169B
    implicit none
    integer(8)::N,i
    integer(16)::ans
    integer(8),allocatable,dimension(:)::A
    read*,N
    allocate(A(N))
    read*,A
    call heapsort(N,A)
    if(A(1)==0)then
        print'(i0)',0
    else
        ans=1
        do i=1,N
            ans=ans*A(i)
            if(ans>10_8**18)then
                ans=-1
                exit
            end if
        end do
        print'(i0)',ans
    end if
end program ABC169B

subroutine heapsort(n,array)
    implicit none
    integer(8),intent(in) :: n
    integer(8),intent(inout) :: array(1:n)
   
    integer(8) ::i,k,j,l
    integer(8) :: t
   
    if(n.eq.1)return
  
    l=n/2+1
    k=n
    do while(k.ne.1)
       if(l.gt.1)then
          l=l-1
          t=array(L)
       else
          t=array(k)
          array(k)=array(1)
          k=k-1
          if(k.eq.1) then
             array(1)=t
             exit
          endif
       endif
       i=l
       j=l+l
       do while(j.le.k)
          if(j.lt.k)then
             if(array(j).lt.array(j+1))j=j+1
          endif
          if (t.lt.array(j))then
             array(i)=array(j)
             i=j
             j=j+j
          else
             j=k+1
          endif
       enddo
       array(i)=t
    enddo
  
    return
end subroutine heapsort