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
t = int(input())
for k in range(t):
  a, b = input().split()
  a = int(a)
  b = int(b)
  period = 0
  suma = 0
  for i in range(2,1000):
      suma += (b*i)%10
      if (i*b) % 10 == b%10:
          period = i - 1
          break
  c = a // b

  ans = suma * (c // period)
  if c%period != 0:
      for i in range(1, c%period  + 1):
         ans += (b*i)%10
  print(ans)
