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
# mod 10までと考えていい
# 1→ 1 2 3 4 5 6 7 8 9 0
# 2→2 4 6 8 10
# 3→3 6 9 2 5 8 1 4 7 0
# 4 →
q = int(input())

anss = []
for i in range(q):
    n,m = map(int, input().split())
    k = m%10
    ans = 0
    if k:
        r = [k]
        while (r[-1]+k)%10 not in r:
            r.append((r[-1]+k)%10)
        l = n//m
        len_r = len(r)
        for j, a in enumerate(r):
            ans += a*(l//len_r + int(j < l%len_r))
    anss.append(ans)

print(*anss, sep="\n")