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
def find_possibles(n):
    p = [n]
    i = 2
    while p[-1] % 10 != 0:
        p.append(n*i)
        i += 1
    return [i % 10 for i in p]


if __name__ == '__main__':
    n = int(input())

    for i in range(n):
        pages, m = map(int, input().split())
        possibles = find_possibles(m % 10)
        n_mul = pages // m
        n_pos = len(possibles)

        print((n_mul // n_pos) * sum(possibles) + sum(possibles[:(n_mul % n_pos)]))
 	 		     	 	      	  				 			