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_sum_of_digits(num_pages, div):
    possible_digits = []
    dig = div % 10
    while dig not in possible_digits:
        possible_digits.append(dig)
        dig = (dig+div) % 10
    times_sum_included = num_pages//(len(possible_digits)*div)
    modulo = num_pages - len(possible_digits)*div*times_sum_included
    return sum(possible_digits)*times_sum_included + sum(possible_digits[:modulo//div])


def read_input(flag=0):
    if flag > 0:
        return int(input())
    return [int(i) for i in input().split()]

if __name__ == '__main__':
    q = read_input(1)
    for i in range(q):
        n,m = read_input()
        print(find_sum_of_digits(n,m))