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 summa(n, m):
    if n < m:
        return 0
    elif n == m:
        return n % 10
    else:
        s = 0
        res = n // m
        b = []
        i = 0
        while True:
            b.append((m * (i + 1)) % 10)
            if len(b) > 2:
                if b[-1] == b[1] and b[-2] == b[0]:
                    b.pop()
                    b.pop()
                    break
            i += 1
        pred_s = sum(b)
        length = len(b)
        p = res//length
        s += p*pred_s
        l = res%length
        for k in range(l):
            s += b[k]
        return s


q = int(input())
for i in range(q):
    a, b = map(int, input().split())
    print(summa(a, b))
