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())
arr = [[0],[0,1,2,3,4,5,6,7,8,9],[0,2,4,6,8],[0,3,6,9,2,5,8,1,4,7],[0,4,8,2,6],[0,5],[0,6,2,8,4],[0,7,4,1,8,5,2,9,6,3],[0,8,6,4,2],[0,9,8,7,6,5,4,3,2,1]]
arr1 = [[0,1],[45,10],[20,5],[45,10],[20,5],[5,2],[20,5],[45,10],[20,5],[45,10]]
for i in range(q):
	n,m = map(int,input().split(" "))
	m1 = m%10
	a = n//m
	sum1 = 0
	sum1+=arr1[m1][0]*(a//arr1[m1][1])
	r = a%arr1[m1][1]
	for i in range(r+1):
		sum1+=arr[m1][i]

	print(sum1)


