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 Main{
	public static void  main(String[] args)
	{
	    Scanner sc = new Scanner(System.in);
	    int t= sc.nextInt();
	    while(t-->0)
	    {
	    	int a[] = {0,1,2,3,4,5,6,7,8,9};
	    	long n = sc.nextLong();
	    	long q = sc.nextLong();
	    	int t1 = (int)(q%10);
	    	if(t1==0) System.out.println("0");
	    	else if(t1 == 5)
	    	{
	    		long j = n/q;
	    		if(j==1) System.out.println("5");
	    		else
	    		{
	    		long m;
	    		m = j/2;
	    		if(j%2==1) m++;
	    		System.out.println(m*5);
	    		}
	    	}
	    	else
	    	{
	    		if(t1%2==0)
	    		{
	    			long j = n/q;
	    			long m;
	    			int t2 =t1;
	    			m = (j/5) * 20;
	    			long m1 = j%5;
	    			while(m1!=0)
	    			{
	    				m = m + a[t2%10];
	    				t2 = t2 + t1;
	    				m1--;
	    			}
	    			System.out.println(m);
	    		}
	    		else
	    		{
	    			long j = n/q;
	    			long m;
	    			int t2 =t1;
	    			m = (j/10) * 45;
	    			long m1 = j%10;
	    			while(m1!=0)
	    			{
	    				m = m + a[t2%10];
	    				t2 = t2 + t1;
	    				m1--;
	    			}
	    			System.out.println(m);
	    		}
	    	}
	    }
	}
}