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.io.*;
import java.util.stream.Stream;
public class NewMain
{
  
    
    public static void main(String[] args) throws IOException  
    { 
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int t = Integer.parseInt(br.readLine());
        while(t-->0)
        {
            
            String[] str = br.readLine().split(" ");
            long n = Long.parseLong(str[0]);
            long m = Long.parseLong(str[1]);
            long q = n/m;
            long sum=0;
            if(q<=10)
            {
                for(int i=1;i<=q;i++)
                {
                    long prod = m*i;
                    sum+=(prod%10);
                }
                System.out.println(sum);
                continue;
            }
            for(int i=1;i<=10;i++)
            {
                long prod = m*i;
                sum+=(prod%10);
                
            }
            long whole = q/10;
            sum*=whole;
            long rem = q%10;
            for(int i=1;i<=rem;i++)
            {
                long prod = m*i;
                sum+=(prod%10);
            }
            
            System.out.println(sum);
        }
    }
}