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 problem():
    T = int(input())
    while T:
        n,m = [int(x) for x in input().split(' ')]
        k = n//m
        k = k*m
        lines = int(k/(10*m))
        offset = int(k%(10*m))
        offset_count = offset//m
        l = list()
        i=1
        while i<=10:
            num = i*m
            l.append(num%10)
            i+=1
        _sum = 0
        i=0
        while i<10:
            _sum += l[i]*lines
            i += 1
        i=0
        while i<offset_count:
            _sum += l[i]
            i += 1
        print(_sum)
        T -= 1

if __name__=='__main__':
    problem()