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():

    n1= int(input())

    for _ in range(n1):

        n, m = map(int, input().rstrip().split())
        arr=[]
        val=0
        for i in range(1,10):
            res = str(m*i)
            arr.append(int(res[-1])) 
            val+=int(res[-1])

        div = n//m
        mul = div//10
        add = div%10

        val = val*mul
        for i in range(add):
            val+=arr[i]

        print(val)

if __name__ == "__main__":
    main()