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
arr = [[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 45],
    [2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 40],
    [3, 6, 9, 2, 5, 8, 1, 4, 7, 0, 45],
    [4, 8, 2, 6, 0, 4, 8, 2, 6, 0, 40],
    [5, 0, 5, 0, 5, 0, 5, 0, 5, 0, 25],
    [6, 2, 8, 4, 0, 6, 2, 8, 4, 0, 40],
    [7, 4, 1, 8, 5, 2, 9, 6, 3, 0, 45],
    [8, 6, 4, 2, 0, 8, 6, 4, 2, 0, 40],
    [9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 45] ]

def func(q, lastDigit):
    sum = 0
    for i in range(q%10):
        sum += arr[lastDigit][i]
    sum += (arr[lastDigit][10] * (q//10))
    print(sum)
    return

testCase = int(input())

for i in range(testCase):
    n, m = input().split()
    n = int(n)
    m = int(m)
    lastDigit = m % 10
    func(n//m, lastDigit)