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.lang.*;
import java.io.*;
public class Codechef
{
    public static void main (String[] args) throws java.lang.Exception
    {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        while(t-- > 0) {
            long n = sc.nextLong();
            long m1 = sc.nextLong();
            long cnt = 0;
            int i = 1;
            long lim = (n / m1);
            lim = lim / 10;
            int m = (int)(m1 % (long)10);
            int ar[] = new int[10];
            while(i < 10) {
                ar[i] = ar[i - 1] + ((m * i) % 10); 
                i++;
            }
            cnt += (lim) * (ar[9]);
            cnt += ar[(int)((n / m1) % 10)];
            System.out.println(cnt);
            
        }
    }
    
}