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
import sys
input = sys.stdin.readline
ins = lambda: input().rstrip()
ini = lambda: int(input().rstrip())
inm = lambda: map(int, input().rstrip().split())
inl = lambda: list(map(int, input().split()))
out = lambda x, s='\n': print(s.join(map(str, x)))

t = ini()
for _ in range(t):
    n, m = inm()
    first = []
    for i in range(1, 11):
        first.append(int(str(m*i)[-1]))
    ans = 0
    if n >= m * 10:
        ans += n // (m*10) * sum(first) + sum(first[:(n % (m*10) // m)])
    elif n >= m:
        ans += sum(first[:n//m])
    print(ans)