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
#!/usr/bin/env python3
import sys
import itertools

q = None
for c, line in zip(itertools.count(), sys.stdin):
    if c == 0:
        q = int(line)
    elif c - 1 > q:
        break
    else:
        n, m = map(int, line.split(' '))
        j = (n // m)

        k = j % 10
        j = j // 10

        res = sum([((_ * m) % 10) for _ in range(10)]) * j + sum([((_ * m) % 10) for _ in range(k+1)])
        print(res)
