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
def f(n,m):
	s = 0
	if(n>m*10):
			for i in range(m,m*10,m):
				s += int(str(i)[len(str(i))-1])
			s = s*int(n/(m*10))
			for i in range(m*int(n/(m*10))*10,n+1,m):
				s += int(str(i)[len(str(i))-1])
			return s
	else:
		for i in range(m,n+1,m):
			s += int(str(i)[len(str(i))-1])
		return s


nt = int(input())
ans = []
for i in range(nt):
    n,m= input().split()
    ans.append(f(int(n),int(m)))
for i in ans:
    print(i)
