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.*;
import java.io.*;

public class main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int t = sc.nextInt();
		while (t > 0) {
			t--;
			long sum = 0,total=0;
			long n = sc.nextLong();
			long m=sc.nextLong();
			long q=n/m;long[] arr=new long[10];
			for(int i=0;i<10;i++) {
				long p=m*i;
				sum+=(p%10);
				arr[i]=sum;
			}
			total=(sum*(q/10));
			int j=(int)(q%10);
			total+=arr[j];
			
			System.out.println(total);
		}
	}
}
