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 practice(n,m):
    if m>n:
        return 0
    elif n<=10:
        count=0
        no=1
        i=1
        while True:
            no=m*i
            i=i+1
            if no>n:
                break
            count+=int(str(no)[-1])
        return count
    else:
        count=[]
        no=1
        i=1
        while True:
            no=m*i
            i=i+1
            if i>10:
                break
            count.append(int(str(no)[-1]))
       
        y=(n//m)
        x=(y//10)
        a=(sum(count)*x)
        b=sum(count[:(y-(10*x))])
        ans=a+b
     
        return ans


n=int(input())
ans=[]
for x in range(n):
    arr=[int(i) for i in input().split()]
  
    value=practice(arr[0],arr[1])
    ans.append(value)
   
  
for a in ans:
    print(a)