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;
var 
    ans : QWord;
    a, i : integer;
    ar : array[1..100000] of QWord;
begin
    readln(a);
    ans := 1;
    for i := 1 to a do 
        begin 
            read(ar[i]);    
            if ( ar[i] = 0 ) then 
                begin 
                    writeln('0');
                    exit;
                end;
        end;
    for i := 1 to a do 
        begin
            if ans > 1000000000000000000 div ar[i] then 
                    begin
                        writeln('-1');
                        exit;
                    end;
            ans := ans * ar[i];
        end;
        
    writeln(ans);
end.