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(0, T):
	inp = input()
	array_inp = inp.split(" ")
	n = int(array_inp[0])
	m = int(array_inp[1])
	q = n//m
	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], [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]]
	last_dig = m%10
	value = (q//len(arr[last_dig]))*sum(arr[last_dig])
	for i in range (0, q%len(arr[last_dig])):
		value = value + arr[last_dig][i]
	print(value)