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
dic = {
    0: [0],
    1: [1,2,3,4,5,6,7,8,9,0],
    2: [2,4,6,8,0],
    3: [3,6,9,2,5,8,1,4,7,0],
    4: [4,8,2,6,0],
    5: [5,0],
    6: [6,2,8,4,0],
    7: [7,4,1,8,5,2,9,6,3,0],
    8: [8,6,4,2,0],
    9: [9,8,7,6,5,4,3,2,1,0]
}
l = [sum(dic[i]) for i in range(10)]

q = int(input())
for _ in range(q):
    n,m = map(int,input().split())
    pages = n//m
    m = str(m)
    last = int(m[-1])
    
    ans = pages//len(dic[last])
#     print(ans,pages,len(dic[last]))
    ans *= l[last]
#     print(pages%len(dic[last]))
    ans += sum(dic[last][ : pages%len(dic[last])])
    print(ans)