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
d={
	"1":[1,2,3,4,5,6,7,8,9,0],
	"2":[2,4,6,8,0,2,4,6,8,0],
	"3":[3,6,9,2,5,8,1,4,7,0],
	"4":[4,8,2,6,0,4,8,2,6,0],
	"5":[5,0,5,0,5,0,5,0,5,0],
	"6":[6,2,8,4,0,6,2,8,4,0],
	"7":[7,4,1,8,5,2,9,6,3,0],
	"8":[8,6,4,2,0,8,6,4,2,0],
	"9":[9,8,7,6,5,4,3,2,1,0]
}
for x in range(int(input())):
	m,n=input().split()
	if n[-1]=="0":print(0)
	else:
		a=int(m)//(int(n)*10)
		b=int(m)%(int(n)*10)
		c=b//int(n)
		print(a*sum(d[n[-1]])+sum(d[n[-1]][:c]))
