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
tensum = {0: 0, 1: 45, 2: 40, 3: 45, 4: 40, 5: 25, 6: 40, 7: 45, 8: 40, 9: 45}

t = int(input())

for tc in range(t):
	n, m = map(int, input().split(' '))
	sum1 = 0
	ud = m % 10	# units digit of the divisor
	rangeMax = n//m
	sum1 += (rangeMax//10) * tensum[ud]
	for i in range(1, rangeMax%10+1):
		sum1 += (i*m)%10
	print(sum1)