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 _ in range(t):
    n,m = map(int,input().split())

    l = []
    i = 0
    while True:
        k = (i*m)%10
        if k in l:
            break
        l.append(k)
        i+=1

    z = ((n//m))//len(l)
    z1 = n//m
    ka = (z1*m)%10


    yo = sum(l)*(z)

    for i in l:
            if i == ka:

                yo+=i

                break
            yo+=i

    print(yo)
