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
#582_C

n = int(input())

ref = []
sums = []
for i in range(0, 10):
    ref.append([])
    for j in range(0, 10):
        ref[-1].append(int(list(str(i * j))[-1]))
    sums.append(sum(ref[-1]))

pref = []
for i in ref:
    pref.append([i[0]])
    for j in range(1, len(i)):
        pref[-1].append(pref[-1][-1] + i[j])

for i in range(0, n):
    ln = [int(j) for j in input().split(" ")]
    a = ln[0]
    b = ln[1]
    dig = int(list(str(b))[-1])
    ct = a // (b * 10)
    rem = (a % (b * 10)) // b
    print(ct * sums[dig] + pref[dig][rem])
