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 answer():
    n, m = map(int, input().split(" "))
    m2 = m % 10

    cumsums = [0]
    last_digits = [0]
    last_digit = 0
    cumsum = 0
    for i in range(10):
        last_digit = (last_digit + m2) % 10
        last_digits.append(last_digit)
        cumsum = cumsum + last_digit
        cumsums.append(cumsum)

    #print("last_digits", last_digits)
    #print("cumsums", cumsums)
    sum_last_digit = sum(last_digits) # 1 - 10 sum

    r1 = n // m
    r2 = r1 // 10
    r3 = r1 % 10
    q = n % m
    #print(r1, r2, r3, q)
    out = r2 * sum_last_digit + cumsums[r3] 
    return out


nn = int(input())
for _ in range(nn):
    out = answer()
    print(out)