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 CodeForces{
public static void main(String[] args) {
		 Scanner sc=new Scanner(System.in);
			        
			        int t=sc.nextInt();
			        
			        while(t>0){
			            long n=sc.nextLong();
			            long m=sc.nextLong();
			            long sum=0;
			            long div=n/m;
			            long full=div/10;
			            long half=div%10;
			            long num=m;
			            for(int i=1;i<=10;i++){
			               long k=num%10;
			               if(i<=half) {
			            	   k*=1+full;
			               }else {
			            	   k*=full;
			               }
			               sum+=k;
			               num+=m;
			            }
			            System.out.println(sum);
			            t--;
			        }
			
	}
}