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())

def func(n,m):
	sum=0
	x=n//m
	a=x//10
	b=x%10
	if m%2!=0:
		if m%5==0:
			sum=a*25
		else:
			sum=a*45
	else:
		if m%10==0:
			sum=0
		else:
			sum=a*40
	for i in range(1,b+1):
		sum=sum+int(str(i*m)[-1])
	return sum

for _ in range(q):
	l=list(map(int,input().split()))
	n,m=l[0],l[1]
	print(func(n,m))