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 main
  implicit none
  integer(8) i, N, ans, lim, frag, frag2
  integer(8),allocatable :: A(:)
  read(*, *)N
  allocate(A(N))
  read(*, *) (A(i), i = 1,N)
  ans = 1
  lim = 1
  frag = 0
  frag2 = 1
  do i = 1,18
    lim = lim * 10
  end do
  !lim = 10**18
  do i = 1,N
    ans = ans*A(i)
    if (ans > lim) then
      frag = 1
    endif
    if (A(i) == 0) then
      frag2 = 0
    endif
  end do
  !frag = frag * frag2
  if (frag == 1) then
    ans = -1
  end if
  if (frag2 == 0) then
    ans = 0
  end if
  write(*, *) ans
end program main