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.*;
public class reading
{
    public static void main(String args[])
    {
        Scanner sc= new Scanner(System.in);
        int test=sc.nextInt();
        for(int i=0;i<test;i++)
        {
            long n=sc.nextLong();
            long k=sc.nextLong();
            long s=0;
            for(long j=k;j<=k*10;j=j+k)
            {
                s=s+(j%10);
            }
           long d=n/(k*10);
           s=s*d;
          long num=n%(k*10);
            for(long x=0;x<=num;x=x+k)
{    
     s=s+(x%10);
}
System.out.println(s);
 
        }
    }
}