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.*;
import java.io.*;

public class ReadingBook
{
	public static void main(String args[])
	{
      Scanner sc=new Scanner(System.in);
      int t=sc.nextInt();

      while(t--!=0)
      {
         long n=sc.nextLong();
         long q=sc.nextLong();
         long sum=0,j=0,r=0; int i=0;
          r=q%10;
          j=n/q;
        
         if(j>=10)
        { while(i++<10)
         {
           sum+=(r*i)%10;

         }
        }
        sum*=j/10;
        i=0;
         while(i++<j%10)
         {
         	sum+=(r*i)%10;
         }
         System.out.println(sum);
      }
 
     
	}
}