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())

for i in range(q):

	n,m=list(map(int,input().split(" ")))

	cnt=1
	sum1=0

	if n%m==0:
		num=n//m

	else:
		num=(n-n%m)//m


	if num>10:
		sum3=0
		rem=num%10

		for i in range(10):
			d=(m*i)%10
			sum1=sum1+d
			if i<=rem:
				sum3=sum3+d

		sum2=(num-rem)//10

		sum4=sum2*sum1+sum3

		print(sum4)

	else:
		# sum1=0

		for i in range(num+1):
			d=(m*i)%10
			sum1=sum1+d

		print(sum1)


