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
t = int(input())

for i in range(t):
    a = [int(x) for x in input().split()]
    n=a[0]
    m=a[1]
    digit = []
    d = m % 10
    while not digit or digit[0] != d:
        digit.append(d)
        d = (d + m%10) % 10
    cnt = n//m
    res = sum(digit) * (cnt // len(digit))

    if cnt %len(digit):
        res += sum(digit[:cnt %len(digit)])
    print(res)
    
    
