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 Solution{//
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		long t=sc.nextLong();
		long n,m;
		int i,j;
		long sum;
		while(t--!=0)
		{	
			n=sc.nextLong();
			m=sc.nextLong();
			sum=0;
			long a[]=new long [12];
			for(i=1;i<=10;i++)
			{
				a[i]=a[i-1]+((i*m)%10);
			}
			sum=sum+a[10]*(long )Math.floor(n/(m*10));
			sum+=a[(int )((n%(m*10))/m)];
			System.out.println(sum);
		}
	}


}
