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 find_sum(n, m):
    count = 0
    m_sum = []
    for i in range(1, 11):
        m_sum.append((m * i) % 10)
    total_num = n // m
    count += ((total_num // 10) * sum(m_sum))
    for i in range(0, total_num % 10):
        count += m_sum[i]
    return count


if __name__ == '__main__':
    for _ in range(int(input())):
        print(find_sum(*map(int, input().strip().split())))
