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.*;
import java.lang.*;

public class contest{


	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int t = sc.nextInt();
		for(int i=0;i<t;i++){
		     long n = sc.nextLong();
		     long m = sc.nextLong();
		     long unit = m%10;
		     int[] a = new int[10];
		     long sum = 0;
		     for(int j=0;j<10;j++)
		     {
		     	a[j] = (int)unit*(j+1) % 10;
		     	sum = sum + (long)a[j];
		     }

		     long division = n/m;

		     long div1 = division/10;

		     long rem1 = division%10;

		     long result = div1 * sum;

		     for(int j=0;j<rem1;j++){
		     	result = result + a[j];
		     }

		     System.out.println(result);
    	}
    }
}
