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
# 1 - 2 - 3 - 5 ...
# 2 - 4 - 6 - 8 - 0 - 2
# 3 - 6 - 9 - 2 - 5 - 8 - 1 - 4 - 7 - 0


def get_cycle(digit):
    res = [digit]
    while len(res) == 1 or res[-1] != digit:
        res.append((res[-1] + digit)%10)
    return res[:-1]


def solve(n, m):

    relevant = m % 10

    if relevant == 0: return 0
    n_times = n // m

    cycle = get_cycle(relevant)

    cycles = n_times // len(cycle)
    left = n_times % len(cycle)

    return sum(cycle) * cycles + sum(cycle[:left])


# print(solve(1, 1))
#
# exit()
cases = int(input())

for i in range(cases):
    n, m = [int(i) for i in input().split()]
    print(solve(n, m))