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
import sys

q=int(sys.stdin.readline())

ans_arr=[]

for i in range(q):
	[n,m]=[int(i) for i in sys.stdin.readline().split()]

	if(n<m):
		ans_arr.append(str(0))
	elif(n==m):
		ans_arr.append(str(m%10))
	else:
		ten=0
		for i in range(1,11):
			ten+=(m*i)%10

		num=n//(m*10)
		ans=ten*num
		val=n-(num*(m*10))

		for g in range(1,val//m+1):
			ans+=(m*g)%10

		# for g in range(num*(m*10)+1,n+1):
		# 	if(g%m==0):
		# 		ans+=g%10

		ans_arr.append(str(ans))

print("\n".join(ans_arr))




