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
d=[[],[],[],[],[],[],[],[],[],[]]
dd =[0,0,0,0,0,0,0,0,0,0]
for i in range(10):
	d[i].append(i)
	dd[i]+=i
	k=(i+i)%10
	while k!=i:
		d[i].append(k)
		dd[i]+=k
		k=(k+i)%10


q=input()
for i in range(q):
	n = list(map(int,raw_input().split()))
	x=int(n[0]/n[1])
	y=int(x/len(d[n[1]%10]))*dd[n[1]%10]
	for j in range(x%len(d[n[1]%10])):
		y+=d[n[1]%10][j]
	print y
