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 Pascal (FPC 3.0.4) (judge verdict: Accepted)

program main;
uses math;
var i, n : longint;
    m : array [1..100000] of qword;
    p : qword = 1;
    c : boolean = false;
    z : boolean = false;
 
begin
  readln(n);
  for i := 1 to n do
    read(m[i]);
  readln;
  for i := 1 to n do
    if (m[i] = 0) then begin
      z := true;
      break;
    end;
  if not(z) then
    for i := 1 to n do
      if p > 1e18 / m[i] then begin
        c := true;
        break;
      end
      else p := p * m[i];
  if z then
    writeln(p-p)
  else if c then
    writeln('-1')
  else writeln(p);
end.