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.Stack;
public class codeforces{
    public static void main(String[] args) throws IOException{
        InputStreamReader isr=new InputStreamReader(System.in);
        BufferedReader br=new BufferedReader(isr);
        StringBuilder str=new StringBuilder();
        PrintWriter out=new PrintWriter(System.out);
        int t=Integer.parseInt(br.readLine());
        while(t-->0){
            String[] lol=br.readLine().split(" ");
            long n=Long.parseLong(lol[0]);
            long m=Long.parseLong(lol[1]);
            long x=0;
            if(m>n || m%10==0)
            x=0;
            else{
                int[] arr=new int[10];
                for(int i=0;i<10;i++)
                arr[i]=(int) ((m*(i+1))%10);
                long h=n/m;
                int hh=(int) (h%10);
                for(int y:arr)
                x+=(y*(h/10));
                for(int i=0;i<hh;i++)
                x+=arr[i];
            }
            str.append(x+"\n");
        }
        out.print(str);
        out.close();
    }
}