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