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
ld = [
    [0],
    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
    [0, 2, 4, 6, 8],
    [0, 3, 6, 9, 2, 5, 8, 1, 4, 7],
    [0, 4, 8, 2, 6],
    [0, 5],
    [0, 6, 2, 8, 4],
    [0, 7, 4, 1, 8, 5, 2, 9, 6, 3],
    [0, 8, 6, 4, 2],
    [0, 9, 8, 7, 6, 5, 4, 3, 2, 1]
]
ldsum = [sum(x) for x in ld]
q = int(input())
for i in range(q):
    n, m = [int(x) for x in input().split()]
    a = m % 10
    if(a == 0):
        print('0')
    else:
        b = n//m
        div = b//len(ld[a])
        rem = b % len(ld[a])
        print(ldsum[a]*div + sum(ld[a][:rem+1]))
