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.Scanner;

public class Problem3 {

	public static void main(String[] args) {
		Scanner scanner =new Scanner(System.in);
		int t;
		t=scanner.nextInt();
		for(int k=0;k<t;k++)
		{
			long n;
			long m;
			n=scanner.nextLong();
			m=scanner.nextLong();
			long x=(n/m)+1;

			long sum=0;
			long z;
			long y;
			y=m%10;

			for(int i=1;i<10;i++)
			{	
				z=i%10;
				sum+=(y*z)%10;
			}
			sum=sum*(n/(10*m));
			long a=(n-((n/(10*m)*10*m)))/m +1;
			for(int i=1;i<a;i++)
			{
				z=i%10;
				sum+=(y*z)%10;
			}
			System.out.println(sum);
		}
	}
}