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 solve(n,m,ans):
    if m > n:
        ans.append(0)
        return
    nums = []
    curr = m%10
    k = 1
    while curr not in nums:
        nums.append(curr)
        k += 1
        curr = (k*m)%10

    total = 0
    k -= 1
    while n > 0 and k > 0:
        total += n//(m*k)*sum(nums)
        n = n%(m*k)
        #print(n,k)
        k -= 1
        nums.pop()

    ans.append(total)

def main():
    q = int(input())
    ans = []
    for i in range(q):
        n,m = map(int,input().split())
        solve(n,m,ans)

    for i in ans:
        print(i)

main()
