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())
while(t>0):
      n,k = map(int , input().split())
      if(k>n or k%10 == 0):
            print(0)
      else:
            if(k%2==0):
                  mul = int((n//k)//5)
                  rem = int((n//k)%5)
                  ans = mul*20
                  for i in range(1 , rem+1):
                        ans=ans+int((k*i))%10
                  print(ans)
            else:
                  if(k%5==0):
                        mul = (n//k)//2 + int((n//k)%2)
                        ans = mul*5
                        print(ans)
                  else:
                        mul = (n//k)//10
                        rem = int((n//k)%10)
                        ans = mul*45
                        for i in range(1,rem+1):
                              ans=ans+int((k*i)%10)
                        print(ans)
      t = t-1
