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
import sys


def main():
    q = int(sys.stdin.readline().strip())
    for _ in range(q):
        # k = int(sys.stdin.readline().strip())
        n, m = [int(s) for s in sys.stdin.readline().strip().split()]
        n //= m

        ds = set()
        x = m
        while x % 10 not in ds:
            ds.add(x % 10)
            x += m

        res = sum(ds) * (n // len(ds))
        n %= len(ds)

        x = m
        while n > 0:
            res += x % 10
            x += m
            n -= 1

        print(res)

main()
