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
t=int(input())
for nt in range(t):
	n,m=map(int,input().split())
	num=n//10
	new = num//m
	x=int(str(m)[-1])
	if (x==1 or x==3 or x==7 or x==9):
		ans=new*45
		num2 = n-(new*m*10)
		#print (ans,new,num2)
		for i in range(1,10):
			if (m*i)<=num2:
				ans+=(int(str(m*i)[-1]))
			else:
				break
	elif (x==4 or x==8 or x==2 or x==6):
		ans=new*40
		num2 = n-(new*m*10)
		#print (ans,new,num2)
		for i in range(1,10):
			if (m*i)<=num2:
				ans+=(int(str(m*i)[-1]))
			else:
				break
	else:
		if x==0:
			ans=0
		else:
			ans=new*25
			num2 = n-(new*m*10)
			#print (ans,new,num2)
			for i in range(1,10):
				if (m*i)<=num2:
					ans+=(int(str(m*i)[-1]))
				else:
					break
	print (ans)