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 e in range(t):
    a, b = input().split()
    a = int(a)
    b = int(b)
    k = b % 10
    c = b
    ost = [0, k]
    while 1:
        c += b
        d = c % 10
        if d == k:
            break
        ost.append(d)
        ost[-1] += ost[-2]
    ost.pop()
    print(ost[-1] * (a // b // len(ost)) + ost[a // b % len(ost)])
