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
def inp():
    return map(int, input().split())


from math import *

q = int(input())
for i in range(q):
    n, m = inp()
    out, dig = 0, m % 10
    if (dig == 5):
        if ((n // m) % 2):
            out = ceil((n // m) / 2) * 5
        else:
            out = ((n // m) // 2) * 5
    elif (dig == 0):
        out = 0
    else:
        if (dig % 2):
            sum, c = 45, 10
        else:
            sum, c = 20, 5
        div, count = n // m, dig
        out += (div // c) * sum
        for i in range(div % c):
            if (count > 9):
                count %= 10
            out += count
            count += dig

    print(out)
