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
def fond(j):
	k = j % 10
	if k == 1 or k == 3 or k == 7 or k == 9:
		return 45
	elif k == 2 or k == 4 or k == 6 or k == 8:
		return 40
	elif k == 5:
		return 25
	else:
		return 0

def sumy(a, b):
	w = a % 10
	s = 0
	for y in range(1, b + 1):
		r = (w * y) % 10
		s += r
	return s
		
q = int(input())
for i in range(q):
	n, m = map(int, input().split())
	p = n // (10 * m)
	f = p * fond(m)
	p = (n // m) - 10 * p
	f += sumy(m, p)
	print(f)