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
number = int(input())
for i in range(number):
    tem = input()
    data = tem.split()
    page = int(data[0])
    div = int(data[1])
    div_list = [div%10]
    tem = div%10
    while True:
        tem = (tem + div%10)%10
        if tem != div_list[0]:
            div_list.append(tem)
        else:
            break
    no = len(div_list)
    total = 0
    for i in div_list:
        total+=i
    loop = (page//div)//no
    rem = (page//div)%no
    tem_total = 0
    for i in range(rem):
        tem_total += div_list[i]
    print(tem_total + loop * total)
