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
try:
    test=int(input())
    while test:
        test-=1
       
        n,m=map(int,input().split())
        if m==n:
            m=str(m)
            print(m[len(m)-1])
        elif m>n:
            print(0)
        elif m==1:
            t=n//10
            re=n-(10*t)
            print(((re*(re+1))//2)+(45*t))
        else:
            ns=0
            for i in range(1,10):
                nu=m*i
                nu=str(nu)
                ns+=int(nu[len(nu)-1])
            #print(ns)
            di=n//m
            
            t=di//10
            re=di-(10*t)
            curr=0
            for i in range(1,re+1):
                nu=m*i
                nu=str(nu)
                curr+=int(nu[len(nu)-1])
            print(curr+(ns*t))
except:
    pass           
        
            