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 BookReading {
	public static void main(String[]args)
	{
		Scanner scan=new Scanner(System.in);
		int q=scan.nextInt();
		int[] sumDivisors= {45,20,45,20,5,20,45,20,45};
		for(int i=0;i<q;i++)
		{
			long sum=0;
			long remain=0;
			long n=scan.nextLong();
			long m=scan.nextLong();
			int last=(int)(m%10);
			long quotient=(n/m);
			if(last==5)
			{
				remain=quotient%2;
				quotient/=2;
			}else if(last%2==0)
			{
				remain=quotient%5;
				quotient/=5;
			}else 
			{
				remain=quotient%10;
				quotient/=10;
			}
			if(last!=0)
			{
			sum=quotient*sumDivisors[last-1];
			for(int j=1;j<=remain;j++)
			{
				sum+=(last*j)%10;
			}
			}
			System.out.println(sum);
		}
	}
}
