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 DivA {

    private static StringTokenizer st;
    private static BufferedReader br;
    private static PrintWriter pw;
    static String str = "Value 1";
    private static void changeIt(String s){
        s = s + "Value 2";
    }
    public static void main(String[] args) throws IOException {
        br = new BufferedReader(new InputStreamReader(System.in));
        pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
        int a[] = new int[11];
        for(int i = 0 ; i <= 9;i++){
            int ans = 0;
            for(int j = 1 ; j <= 10;j++){
                ans += (i * j) % 10;
            }
            a[i] = ans;
        }
        int t;
        t = nextInt();
        while(t-- >= 1)
        {
        long ans = 0;
        long n = nextLong();
        long m = nextLong();
        long temp = n / m;
        long on = temp / 10;
        ans += (on) * a[(int) (m%10)];
        temp -= on * 10;
        long start = m;
        for(int i = 1 ; i <= temp ;i ++){
            ans += (start*i)  % 10;
        }
        System.out.println(ans);
        }


        pw.close();
    }

    private static int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    private static long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    private static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    private static String next() throws IOException {
        while (st==null || !st.hasMoreTokens())
            st = new StringTokenizer(br.readLine());
        return st.nextToken();
    }
}
