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 BookReading_C {

	static long []sum= {0,45,40,45,40,25,40,45,40,45,0};
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn=new Scanner(System.in);
		int t=scn.nextInt();
		for(int i=0;i<t;i++) {
			long n=scn.nextLong();
			long m=scn.nextLong();
			long x=n/m;
			long y=x/10;
			long rem=x%10;
			int z=(int)(m%10);
			int s=0;
			for(int j=1;j<=rem;j++) {
				s+=(z*j)%10;
			}
			//System.out.println("mmmmm "+z+" "+rem+" "+sum[z]+" "+sum[z]*y+" "+s);
			
			System.out.println(sum[z]*y+(s));;
		}
	}

}
