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 last(p):
   return int(str(p)[-1])

for _ in range(int(input())):
   pages, a = map(int, input().split())
   n = pages//a
   lst = a*n
   dig = int(str(a)[-1])
   if dig==0:
      print(0)
      continue

   d = {1:[10, 45], 2:[5, 20], 3: [10, 45],
        4:[5, 20], 5:[2, 5], 6:[5, 20],
        7:[10, 45], 8:[5, 20], 9:[10, 45]}

   div = d[dig][0]*a
   perf = pages//div
   rem = pages%div
   ans = perf*d[dig][1]
   tmp = a
   while tmp<=rem:
      ans+=last(tmp)
      tmp+=a

   print(ans)
   
