How can I decrease the running time and compile time of the following code?Given three integers A, B and K, you need to report the Kth number  between A and B (both inclusive), satisfying the property that: the  number does not contain a digit 'zero' and product of digits of number  is a perfect square. If there doesn't exist that Kth number output  -1(without quotes).Input:First Line contains the number of test cases \$T\$. Next \$T\$ lines contain 3  space separated integers A, B, K as mentioned in the task.Output:Output \$T\$ lines as answer for every test case.Constraints:\$1  T  100\$  \$1  A  B  10^{18}\$  \$1  K  10^7\$  Sample input:3 1 10 48 14 21 1000 23Output:-111119public static void main(String[] args) {    Scanner in = new Scanner(System.in);    int cases = in.nextInt();    long A,B,K;    int caseNum =0;    while(caseNum < cases)    {        A = in.nextLong();        B = in.nextLong();        K = in.nextLong();        ArrayList<Long> products = new ArrayList<>();        long product = 1;        for(long i=A,k=0;i<=B && k<(B-A+1);i++,k++)        {            long num = i;            double sqrt;            ArrayList<Long> temp = new ArrayList<>();            while(num>0)            {                temp.add(num%10);                num = num/10;            }            for(int j=0;j<temp.size();j++)            {                if(temp.get(j)==0){                    product=-1;                    break;                }                product = product*temp.get(j);                //System.out.println(Currently processing: + temp.get(j));            }            sqrt = Math.sqrt(product);            if( product%sqrt==0)            {   products.add(i);            }            product=1;          }        try{            System.out.println(products.get((int)K-1));        }catch (Exception e) {            // TODO: handle exception            System.out.println(-1);        }        caseNum++;    }}}
How do I decrease compile time and execution time of following program?
java;optimization;programming challenge