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
q = int(input())
for _ in range(q):
    n, m = map(int, input().split())
    if m % 10 == 0:
        x, y = 1, 0
    elif m % 2 == 0:
        x, y = 5, 20
    elif m % 5 == 0:
        x, y = 2, 5
    else:
        x, y = 10, 45
    c = n // m
    ans = c // x * y
    if c > 0:
        d = c % x
        for i in range(d):
            ans += m * (i + 1) % 10
    print(ans)
