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 NewClass1 
{
    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        while(t-->0)
        {
            long n = sc.nextLong();
            long m = sc.nextLong();
            if(m>n)
            {
                System.out.println("0");
            }
            else
            {
            long digit = (m%10);
            long temp = m;
            long sum = digit;
            while((temp+m)%10!=digit && (temp+m)<=n)
            {
                sum+=(temp+m)%10;
                temp = temp+m;
            }
            if(temp<n)
            {
                sum = (n/temp)*sum;
                temp = temp*(n/temp);
            }
            temp+=m;
            while(temp<=n)
            {
                sum +=(temp%10);
                temp+=m;
            }
            System.out.println(sum);
            }
        }
    }
}
