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
for _ in range(int(input())):
    n,m=map(int,input().split())
    if m>n:
        print(0)
    else:
        d={'0':[0],'1':[1,2,3,4,5,6,7,8,9,0],'2':[2,4,6,8,0],'3':[3,6,9,2,5,8,1,4,7,0],'4':[4,8,2,6,0],'5':[5,0],
           '6':[6,2,8,4,0],'7':[7,4,1,8,5,2,9,6,3,0],'8':[8,6,4,2,0],'9':[9,8,7,6,5,4,3,2,1,0]}
        l=str(m)[-1]
        r=n//m
        li=d[l]
        r1=r//len(li)
        r2=r%len(li)
        print(int(sum(li)*r1+sum(li[:r2])))
        
                