Polycarp is reading a book consisting of n pages numbered from 1 to n. Every time he finishes the page with the number divisible by m, he writes down the last digit of this page number. For example, if n=15 and m=5, pages divisible by m are 5, 10, 15. Their last digits are 5, 0, 5 correspondingly, their sum is 10.

Your task is to calculate the sum of all digits Polycarp has written down.

You have to answer q independent queries.

Input

The first line of the input contains one integer q (1 ≤ q ≤ 1000) — the number of queries.

The following q lines contain queries, one per line. Each query is given as two integers n and m (1 ≤ n, m ≤ 10^{16}) — the number of pages in the book and required divisor, respectively.

Output

For each query print the answer for it — the sum of digits written down by Polycarp.

Example

Input


7
1 1
10 1
100 3
1024 14
998244353 1337
123 144
1234312817382646 13


Output


1
45
153
294
3359835
0
427262129093995
import java.util.*;

public class Main {



    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        int t=in.nextInt();
        while(t-->0)
        {
            long N=in.nextLong();
            long m=in.nextLong();
            long sum=0;
            long wholesum=0;
            long size=N/m;
            long x=size%10;
            long y=size/10;
            for(long i=1;i<=10;i++)
            {
                if(i<=x)
                {
                    sum=sum+(m*i)%10;
                }
                wholesum=wholesum+(m*i)%10;
            }
            System.out.println(sum+(wholesum*y));

        }
    }

}
