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 test
{
    public static void main(String args[])
    {
        Scanner s = new Scanner(System.in);
        int q=s.nextInt();
        while(q-->0)
        {
            long n=s.nextLong(),m=s.nextLong();
            long reps=n/m;
            long arr[]=new long[9],sum=0;
            for (int i = 0; i < 9; i++) 
            {
                arr[i]=(m*(i+1))%10;
                sum+=arr[i];
            }
            long ans=0;
            ans+=sum*(reps/10);
            for (int i = 0; i < reps%10; i++) {
                ans+=arr[i];
            }
            System.out.println(ans);
        }
    }
}
