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
# Idea: there should be a cycle for any given divisor

Q = int(input())

# Pregenerate cycles
cycles = dict()
for i in range(0,10):
    c = []
    count = 1
    while True:
        lastdigit = int(str(count*i)[-1])
        # print(i, lastdigit)
        if lastdigit not in c:
            c.append(lastdigit)
        else:
            break
        count += 1
    cycles[i] = c

for k in range(Q):
    N, M = [int(x) for x in input().split(' ')]
    numreq = N//M
    cycledata = cycles[int(str(M)[-1])]
    print(
        (numreq//len(cycledata)*sum(cycledata) +
            sum(cycledata[:numreq%len(cycledata)]))
    )


