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 practice{

	void work(long n, long m){
		long result = 0;
		long times = n / (m * 10);
		for(long i = m; i <= Math.min(m * 10, n); i += m){
			result += i % 10;
		}
		
		if(times >= 1){
			result *= times;
			for(long i = m * 10 * times + m; i <= n; i += m){
				result += i % 10;
			}
		}
		System.out.println(+result);
	}

	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		int test = input.nextInt();
		while(test-- > 0){
			long n,m;
			n = input.nextLong();
			m = input.nextLong();
			practice result = new practice();
			result.work(n, m);
		}
	}
}