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
for _ in range(int(input())):
	n,m=[int(i) for i in input().split()]
	for i in range(1,11):
		if((m*i)%10==0):
			temp=i
			break
	s=0
	for i in range(1,temp+1):
		s+=(m*i)%10
	temp2=n//(temp*m)
	S=temp2*s
	n-=(temp*m)*temp2
	x=n//m
	for i in range(1,x+1):
		S+=(m*i)%10
	print(S)