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
arr = [[0], [1, 2, 3, 4, 5, 6, 7, 8, 9, 0], [2, 4, 6, 8, 0], [3, 6, 9, 2, 5, 8, 1, 4, 7, 0], [4, 8, 2, 6, 0], [5, 0], [6, 2, 8, 4, 0], [7, 4, 1, 8, 5, 2, 9, 6, 3, 0], [8, 6, 4, 2, 0], [i for i in range(9, -1, -1)]]

t = int(input())

output = []
for i in range(t):
	n, m = input().split()
	n = int(n)
	o = int(m)
	m = int(m[-1])

	t = n // o

	l = len(arr[m])
	s = sum(arr[m])

	q = t // l
	r = t % l

	ans = q * s + sum(arr[m][:r])
	output.append(str(ans))

print('\n'.join(output))