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
a1=[1,2,3,4,5,6,7,8,9,0]
a2=[2,4,6,8,0]
a3=[3,6,9,2,5,8,1,4,7,0]
a4=[4,8,2,6,0]
a5=[5,0]
a6=[6,2,8,4,0]
a7=[7,4,1,8,5,2,9,6,3,0]
a8=[8,6,4,2,0]
a9=[9,8,7,6,5,4,3,2,1,0]

a=[a1,a2,a3,a4,a5,a6,a7,a8,a9]

t=int(input())
def solve(n,m):
    count=0
    if(n%10==0):
        return 0
    count+=compute(n,m,n%10)
    n//=10
    return count    
        
        
def compute(n,m,o):
    p=m//n
    q=p//len(a[o-1])
    r=p%len(a[o-1])
    d=q*sum(a[o-1])+sum(a[o-1][:r])
    return d
    
while t>0:
    t-=1
    m,n=input().split()
    n=int(n)
    m=int(m)
    print(solve(n,m))
    