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
q = int(input())
period = [[],[0,1,2,3,4,5,6,7,8,9],[0,2,4,6,8],[0,3,6,9,2,5,8,1,4,7],[0,4,8,2,6],[0,5],[0,6,2,8,4],[0,7,4,1,8,5,2,9,6,3],[0,8,6,4,2],[0,9,8,7,6,5,4,3,2,1]]
psum = [sum(x) for x in period]
for i in range(q):
    n,m = (int(x) for x in input().split())
    a = m % 10
    if a == 0:
        print('0')
    else:
        b = n // m
        dm = divmod(b,len(period[a]))
        print(psum[a]*dm[0]+sum(period[a][:dm[1]+1]))