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
Q = int(input())
lo = []
sm = []
for i in range(10):
	t = []
	for j in range(1, 11): t.append((i * j) % 10)
	lo.append(t)
	sm.append(sum(t))
for i in range(Q):
	N, M = [int(x) for x in input().split()]
	e = int(str(M)[-1])
	ans = ((N // (10 * M)) * sm[e]) + (sum(lo[e][:(N % (10 * M)) // M]))
	print(ans)
