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=map(int,input().split())
	if(m%10==0):
		print(0)
	elif(n>=m):
		s=0
		l=[]
		m=str(m)
		x=int(m[-1])
		m=int(m)
		for i in range(1,x*10):
			if(i%x==0):
				s=s+(i%10)
				l.append(i%10)
		e=(n//(m*10))
		x=((n%(m*10)))//m
		s=s*e
		for j in range(x):
			s=s+l[j]
		print(s)
	else:
		print(0)