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
import math

q = int(input())

for _ in range(q):
  n, m = [int(x) for x in input().split()]

  last = []
  i = k = m % 10
  while i % 10 != 0:
    last.append(i % 10)
    i += k

  last += [0]

  s = sum(last)
  times = 0
  ans = end = 0

  if n >= len(last) * m:
    end = (m * len(last))
  
    times = (n // end)

    ans = s * times

  for i in range(0, (n - end * times) // m):
    ans += last[i]

  print(ans)

  		  						 	   	 			  	 	 			