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
q=int(input())
l1=[1,2,3,4,5,6,7,8,9,0]
s1=45
l2=[2,4,6,8,0]
s2=20
l3=[3,6,9,2,5,8,1,4,7,0]
s3=45
l4=[4,8,2,6,0]
s4=20
l5=[5,0]
s5=5
l6=[6,2,8,4,0]
s6=20
l7=[7,4,1,8,5,2,9,6,3,0]
s7=45
l8=[8,6,4,2,0]
s8=20
l9=[9,8,7,6,5,4,3,2,1,0]
s9=45
for qi in range(q):
    n,m=(int(i) for i in input().split(" "))
    if m>n or m%10==0:
        print(0)
    else:
        d=n//m
        last=m%10
        su=d//len(eval("l%d"%last))
        su*=eval("s%d"%last)
        ite=d%len(eval("l%d"%last))
        for ii in range(ite):
            su+=eval("l%d"%last)[ii]
        print(su)
    	 	 	   		  		 	  	 	 			 	