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 cproblem
{
  public static void main(String args[])
  {
   Scanner in = new Scanner(System.in);
   int t = in.nextInt();
   for(int f =0;f<t;f++)
   {
   	 long n = in.nextLong();
   	 long m = in.nextLong();
   	 long val = n/m;
   	 long find =0;
   	 for(long i=1;i<=9;i++)
   	 {
   	 	 long k =i*m;
   	 	 find = find +k%10;
   	 }
   	 long value = 0;
   	 value = find*(val/10);
   	 long rem = val%10;
   	 for(long i=1;i<=rem;i++)
   	 {
   	 	 long k =i*m;
   	 	 value = value +k%10;
   	 }
   	 System.out.println(value);
   }	
  }	
}