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.*;
public class p3{
    static long parse(String s){
        return Long.parseLong(s);
    }
    public static void main(String args[]) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        long t = parse(br.readLine());
        StringBuilder sb = new StringBuilder();
        int arr[] = new int[10];
        for(int i=1;i<=9;i++){
            int sum=0;
            for(int j=1;j<=9;j++){
                sum += (i*j)%10;
            }
            arr[i] = sum;
        }
        while((t--)>0){
            String params[] = br.readLine().split(" ");
            long n = parse(params[0]);
            long m = parse(params[1]);
            long k = n/m;
            long sum = (k/10)*arr[(int)(m%10)]; 
            for(int i=1;i<=k%10;i++)
                sum+=(i*(m%10))%10;
            sb.append(sum+"\n");
        }
        System.out.print(sb);
    }
}