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 pC
{
	public static void main(String[] args) {
		  Scanner s=new Scanner(System.in);
		   int t=s.nextInt();
                while(t--!=0){
                      long n=s.nextLong();
		        long m=s.nextLong();
                    if(n<m){ System.out.println(0); }
                    else{
	            long k=n/m;
				//System.out.println(k);
                 int sum=0;long res=0;
	            List<Integer>l=new ArrayList<>();
	            for(int i=1;i<11;i++){
	                int xx=(int)((m*i)%10);
					//System.out.println(xx);
	                ///if(!l.contains(xx)){l.add(xx);sum+=xx;}
					l.add(xx);sum+=xx;
	            }
	            //int c=l.size();
	             res+=sum*(k/10);
	             int zz=(int)(k%10);
	            for(int i=0;i<zz;i++){
	                res+=l.get(i);
	            }
                   System.out.println(res); 
                }
        }
	}
}