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
t = int(input())
for i in range(t):
	n, m = map(int, input().split())
	tc = m % 10
	new = tc
	s = n // m
	if s == 0:
		print(0)
	else:
		lst = tc
		tc += new
		tc %= 10
		d = {}
		d[1] = lst
		d[2] = tc
		k = 2
		while lst != tc:
			tc += new
			k += 1
			tc %= 10
			if tc != lst:
				d[k] = tc
		k -= 1
		if s <= k:
			ans = 0
			for i in range(1, s + 1):
				ans += d[i]
			print(ans)
		else:
			dd = s % k
			ans = sum(d.values()) * (s // k)
			for i in range(1, dd + 1):
				ans += d[i]
			print(ans)
