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
for iiiii in range(int(input())):
	n, m = map(int, input().split())
	c = n // m
	l = []
	x = m
	if n < m:
		print(0)
		continue
	while x % 10 not in l and x <= n:
		l.append(x % 10)
		x += m
	s = sum(l)
	ans = s * (c // len(l))
	kek = m * (c // len(l) * len(l) + 1)
	while kek <= n:
		ans += kek % 10
		kek += m
	print(ans)