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.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class G {//
    public static void main(String[] args)throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int q = Integer.parseInt(br.readLine());
        while (q-- > 0) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            long n = Long.parseLong(st.nextToken());
            long m = Long.parseLong(st.nextToken());
            long sum=0;
            for (int i = 1; i <= 9; i++) {
                long single = (m * i) % 10;
                long num = n / m / 10 + (n / m % 10 >= i ? 1 : 0);
                sum += num * single;

            }
            System.out.println(sum);
        }
    }
}

  	 		  			   	   			   	  		