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 problem():
    (num_pages, divisor) = map(int, input().split(" "))
    seen = set()
    for i in range(0, num_pages + 1, divisor):
        candidate = i % 10
        if candidate in seen:
            break
        seen.add(candidate)
    cycle_length = len(seen)
    cycle_value = sum(seen)
    num_written_pages = num_pages // divisor
    num_cycles = num_written_pages // cycle_length
    partial_sum = cycle_value * num_cycles
    remainder_position = num_cycles * cycle_length * divisor
    for i in range(remainder_position, num_pages + 1, divisor):
        partial_sum += i % 10
    print(partial_sum)

if __name__ == '__main__':
    n = int(input())
    for i in range(n):
        problem()
