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
l=[[0],[1,2,3,4,5,6,7,8,9],[2,4,6,8],[3,6,9,2,5,8,1,4,7],[4,8,2,6],[5],[6,2,8,4],[7,4,1,8,5,2,9,6,3],[8,6,4,2],[9,8,7,6,5,4,3,2,1]]
for _ in range(int(input())):
    n,m=map(int,input().split())
    q=n//m
    r=n%m
    x=str(m)
    xx=x[-1]
    val=int(xx)
    ans=0

    t=q//(len(l[val])+1)
    t1=q%(len(l[val])+1)

    ans+=t*(sum(l[val]))
    ans+=sum(l[val][:t1])
    print(ans)
