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.ArrayList;
import java.util.Scanner;

public final class BookReading {
    static Scanner sc = new Scanner(System.in);

    static void solve() {
        long n = sc.nextLong();
        long m = sc.nextLong();
        ArrayList<Long> al = new ArrayList<>();
        for (int i = 1; i <= 10; i++) {
            al.add((m * i) % 10);
        }
        long cycleSum = 0;
        for (long l : al) {
            cycleSum += l;
        }
        long iter = n / m;
        long cycles = iter / 10;
        long rem = iter % 10;
        long ans = cycles * cycleSum;
        for (int i = 0; i < rem; i++) {
            ans += al.get(i);
        }

        System.out.println(ans);
    }

    public static void main(String args[]) {
        int t = sc.nextInt();
        while (t-- > 0) {
            solve();
        }
    }
}
