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.io.*;
import java.util.*;
	 
public class C 
{
	 
	public static void main(String[] args)throws IOException 
	{	
		BufferedReader ob = new BufferedReader(new InputStreamReader(System.in));
		StringBuffer sb = new StringBuffer();
		
		int test=Integer.parseInt(ob.readLine());
		while(test-->0)
		{
			String s[]=ob.readLine().split(" ");
			
			long n=Long.parseLong(s[0]);
			long m=Long.parseLong(s[1]);
			
			long sumt=0L;
			long table[]=new long[11];
			for(int i=1;i<=10;i++)
			{
				table[i]=(m*(long)i)%10;
				sumt+=table[i];
			}
			
			long div=n/m;
			long ans=(div/10L * sumt);
			for(int i=1;i<=div%10;i++)
				ans+=table[i];
			
			sb.append(ans+"\n");
		}
		System.out.println(sb);
	}
		
}