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.*;
import java.util.ArrayList;
public class problem{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		int q=sc.nextInt();
		long  sum=0L;

		ArrayList <Long> arr=new ArrayList<>();

		for(int i=0;i<q;i++){

			sum=0L;

			long n=sc.nextLong();
			long m=sc.nextLong();

			int m_last=(int)(m%10);
			long tenmultiples=n/(10*m);
			
			if(m_last==0){
				sum=0L;
			}
			else if(m_last%5==0){
				sum=tenmultiples*25;
				int left=(int)((n%(10*m))/m);

				for(int j=1;j<=left;j++){
					sum+=(m_last*j)%10;
				}
			}

			else if(m_last%2!=0){
				sum=tenmultiples*45;
				int left=(int)((n%(10*m))/m);

				for(int j=1;j<=left;j++){
					sum+=(m_last*j)%10;
				}
			}
			else{
				sum=tenmultiples*40;
				int left=(int)((n%(10*m))/m);

				for(int j=1;j<=left;j++){
					sum+=(m_last*j)%10;
				}	
			}

			arr.add(sum);
		}
		for(long sums:arr){
			System.out.println(sums);
		}

	}
}

