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.ArrayList;
import java.util.Scanner;

public class question {
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		long q = s.nextInt(), n, m, t1 = 0, t2 = 0, sum = 0;
		ArrayList<Long> al = new ArrayList<Long>();
		for (long i = 0; i < q; i++) {
			n = s.nextLong();
			m = s.nextLong();
			for (long j = 1; j < 11; j++) {
				String st = new String(new Long(m * j).toString());
				t1 = new Long(st.substring(st.length() - 1));
				al.add(t1);
				sum += t1;
			}
			t2 += sum * ((long) (n / m) / al.size());
			for (int j = 0; j < (n / m) % al.size(); j++) {
				t2 += al.get(j);
			}
			 System.out.println(t2);
			t2 = 0;
			sum = 0;
			t1 = 0;
			al.clear();

		}

	}
}
