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 = [int(x) for x in input().split()]
	digs = n//m
	unit = m % 10
	cycle = 0;
	sum = 0;
	if unit in [1,3,7,9]:
		cycle = 10
		sum = 45
	elif unit in [2,4,6,8]:
		cycle = 5
		sum = 20
	elif unit == 5:
		cycle = 2
		sum = 5
	else:
		cycle = 1
		sum = 0
	ans = sum * (digs//cycle)
	digs = digs % cycle
	p = m
	for j in range(digs):
		ans = ans + (p%10)
		p = p + m
	print(ans)
		
		