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
N = int(input())

for i in range(N):
    summary = 0
    sum_cycle = 0
    tmp = input().split()
    tmp = list(map(int, tmp))
    n = tmp[0]
    m = tmp[1]
    mas = []
    cycle = 0
    if m <= n:
        for j in range(10):
            sum_cycle = sum_cycle + m
            cycle += sum_cycle % 10

        summary += cycle * (n // sum_cycle)

        j = 0
        while j <= (n % sum_cycle):
            summary += j % 10
            j = j + m

    print(summary)
