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
for _ in range(int(input())):
    n, m = [int(i) for i in input().split()]
    ans = 0
    if n > 10:
        per = 5 if m % 2 == 0 else 10
        # s = 20 if m % 2 == 0 else 45
        count = n // m
        last = m % 10
        ch = last
        circle = []
        for i in range(per):
            circle.append(ch % 10)
            ch += last
        s = sum(circle)
        ans += (count // per) * s
        pos = count % per
        for i in range(pos):
            ans += circle[i]
    else:
        for i in range(n+1):
            if i % m == 0:
                ans += i % 10
    print(ans)