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())
result = []
for i in range(q):
    list_item = input().split()
    [x, y] = map(int, list_item)
    min_range = 0
    y_mul_ten = y * 10
    for ins in range(1, 10):
        min_range += (y * ins) % 10

    temp = x // y_mul_ten
    rem = x % y_mul_ten
    total = min_range * temp
    index = 1
    while (index * y) <= rem:
        total += (index * y) % 10
        index += 1

    result.append(total)

for i in result:
    print(i)