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
t=int(input())



while t>0 :
        t=t-1
        ans=0
        n,m=[int(x) for x in input().split()]
        l=[]
        r=m
        s=m
        while r!=0:
                l.append(s%10)
                r=s%10
                s=s+m
        noofdiv=n//m
        
        ans=(noofdiv//len(l))*sum(l)
      
        ind=(noofdiv%len(l))
       
        ans=ans+sum(l[:ind])
        print(ans)
        
        
        