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 main():

    tc = int(input())
    while tc > 0:
        tc -= 1
        line = input().split()
        n = int(line[0])
        m = int(line[1])

        d = []
        for i in range(1, 11):
            d.append(i * m)
        
        ans = 0
        g = 10 * m
        cnt = n // g

        for i in range(10):
            ans += cnt * (d[i] % 10)
        
        top = g * cnt

        while top <= n:
            ans += top % 10
            top += m

        print(ans)


main()